Archive of Our Own ^beta

Shiro has a complicated relationship with rules. His grandfather always said they were meant to keep him safe, but Shiro has always thought of them as restrictive, trying to keep him from truly living. He gets they’re supposed to keep him safe — like when he broke his leg after running down the stairs or lost one of his baby teeth by jumping on his bed. But Shiro’s always had a worrying lack of self-preservation, and it makes it difficult for him to follow a rule without knowing why he has to do things a certain way or not do things entirely.

But the rules didn’t protect him from his disease, or the accident that took his arm. Shiro’s ability to bend the rules is the reason why he’s still alive now, along with his crew. But everyone blamed the crash on him, saying he wasn’t following the piloting code, or that he shouldn’t be piloting in the first place when he was sick. No one takes Shiro’s stats and scores in consideration, or his clean record on missions.

Yes, Shiro bent a rule, but for the public, he shattered it to dust.

That’s why he walked out of the Garrison, knowing they’d put the blame entirely on Shiro and hide behind his disease, not caring about how his decisions and abilities saved his crew and cost him an arm. He signed the non-disclosure agreement without a hitch and walked out, trying to find peace in what he had left behind.

Atlas U received him to complete his studies, a stark contrast to other schools avoiding his inscription forms like the pest. They told him he was a good asset to have in their lines and he had been adamant to prove they were right.

He worked his ass off for two years, and he landed a good job as TA for the astrophysics laboratory in his senior year. He will be teaching about what he loves and the working hours are great, giving him enough time in the day to work on his PhD thesis, have three meals a day and an eight-hour sleep, different from how he’d been pulling himself apart and together with a part-time job at the coffeeshop half a city away from both school and his shoebox apartment.

His relationship with the rules is still awkward, but he promised himself to not try his luck with them — he’ll be good and follow every rule, even if it’s as ridiculous as AU's.

Or that is what he keeps telling himself until sin itself walks into his classroom the first day of the semester.

Shiro’s attention drifts inevitably from his notes to the boy walking in. Long legs in tight jeans, red shirt tucked under his belt bringing attention to his impossibly tiny waist. Black hair tied up in a messy bun, leaving his fringe free and framing his face. Sharp jaw, high cheeks, lips pink, eyes dark and surrounded by long lashes. 

Shiro can’t help but stare, latte halfway to his mouth. The boy is handsome, incredibly so, and barely gives Shiro an acknowledging glance before he walks to one of the seats at the back, dropping his backpack there and ruffling through it. 

The rest of the students mill in, and it takes one of them to cough for Shiro to snap out of his thoughts and stand up from his desk, keeping his eyes carefully away from the unassuming student that caught his eye.

“Good morning, class. Welcome to Advanced Physics. My name is Takashi Shirogane and I’m Professor Slav’s TA for this class,” he says with a practiced smile, looking over the faces of his students. He lingers more than he has to on the boy at the back, and has to force himself to look down and away.

His first class goes without much of a problem, and he’s actually relieved that the boy — Keith, his mind unhelpfully reminds him in awe after he made every student introduce themselves just to know his name — didn’t make comments during the class, unlike most of the other students. He seems attentive, writing down everything that Shiro puts on the board or says, but not particularly interested in what he’s teaching.

Other students do try to get his attention, either answering questions or make comments about whatever Shiro is talking about. But even with silence from the back of the classroom, Shiro feels himself burn with Keith’s stare, cheek leaned over his palm and looking too effortlessly attractive for Shiro’s good. It’s until class ends and after Keith walks out that Shiro can finally breathe, skin prickling and hand sweating. 

It’s overwhelming to be so strongly attracted to someone he doesn’t even know. Shiro hasn’t been in a relationship for quite a while because of that same reason. But as he arrives home and remembers long black hair and pretty eyes, he feels helpless to his desires.

For days, the rules about not fraternizing with students dance behind his eyelids whenever he sees Keith step into the classroom, impossibly beautiful with whatever outfit he has on for the day. Sometimes it’s devastating with tight dark jeans and a crop top, or as lazy as an old pair of sweats, an oversized hoodie and hair disheveled.

And yes, the boy might be pretty, and yes, he has a pleasantly rough voice that settles a chill at the base of Shiro’s spine. But if it’s only about his looks, his little crush will flutter away in no time. 

Shiro isn’t a superficial man. He does admire beauty like any other person would, and he does indulge in little stolen glances whenever Keith is absorbed in work. But he needs more than a pretty face and a waist he’s sure he can wrap his hands around and his fingers would meet. Keith is his student, which consequently makes him unreachable, but the way he looks especially bored by whatever Shiro is rambling about in class makes his heart whither in disappointment. He can’t be with someone that is bored by what passions Shiro the most — physics. And it’s a nerdy thing to say, but he is a nerd. It’s at least 48 percent of what shapes Shiro’s every-day conversations, laced with astronomy, sci-fi movies from the 80s and DND.

It makes Shiro wonder why Keith would pick Advanced Physics. It’s one of the optional classes for any of the engineering courses, but it’s not an easy A and the ones who choose it it’s because they need the credits on their study plan. Shiro figures Keith’s situation is the latter, and that’s the reason he keeps to himself every time Shiro throws a question in the air for the students to try and answer.

That is until James, one of the pretentious students that sits at the front and attempts to answer every single one of Shiro’s questions to act like a know-it-all gets one of them wrong.

“It’s not.”

Shiro’s skin rises in goosebumps at the rough voice carrying all the way from the back of the classroom. Everyone looks over to Keith, looking as uninterested as he’s always been in every class.

“Excuse me?” James asks, indignation hanging from his voice, and Keith looks at him in the eye.

“It’s not,” he repeats, unaffected by having everyone’s attention.

“What would you know, dropout?” James bites unkindly, and to Shiro’s horror everyone laughs.

Keith hunches into himself, a muted glare directed at James’ smug smile.

“Actually,” Shiro thunders out, silencing the mean giggles, “Keith is right.”

Mutters go around the classroom, and Shiro stands proud when Keith’s gaze falls on him, stunned someone has stood up for him.

“That was a good catch,” he says, eyes on Keith’s, “Good job.”

Something brightens Keith’s expression, eyes glued to Shiro in a way that makes his skin prickle and cheeks ablaze. 

It isn’t just a crush.

The boy is smart, and he keeps showing it every time Shiro gives him the chance. Not only has he been paying attention to what Shiro has taught, but he’s a step ahead on the topics Shiro has on his plan. It’s impressive how much knowledge Keith has under his belt.

“Have you taken this class before?” he asks one time before he can stop himself, Keith’s retreating back stopping before walking out of the classroom.

He’s been lingering more and more after the bell rings, taking more and more time to gather his things. This time he’s the last to step towards the exit and Shiro can’t resist the little inch of privacy the empty classroom gives them.

“No,” Keith replies, half turned to Shiro, but there’s a bitter curve on his mouth, knowing what Shiro has on his mind even before he asks, “Why?”

Shiro shrugs, looking away at how intensely Keith is staring back at him. “I just thought...”

“That I’ve dropped this class before?” Keith asks, a wary but defensive tone pricking Shiro the wrong way.

Dropout, James had called him that time.

“No,” Shiro shakes his head, watching Keith’s expression soften just a little. “I’m just surprised you know so much. You could’ve jumped right to astrophysics with Professor Slav.”

Keith blinks, shoulders dropping from their guarded position up to his ears. “Oh.” He frowns, hesitating. “Not enough credits.”

Oh, Shiro thinks, that makes sense.

“What a waste,” he whispers without thinking and Keith’s eyes widen slightly.

“Thanks,” he says back, looking away and gesturing outside, “I’ll...”

Shiro nods, not knowing what else to say, and Keith takes it as a queue to turn away and walk out, still giving Shiro a few glances over his shoulder. And it must be Shiro’s crush talking, but he can swear his cheeks were red.

As well as he can swear Keith has been staring at him more often than not. At first Shiro blames it on his imagination. He’s not as attractive as he was once before the accident, with no facial scar, no white hair in his late 20s growing in the front of his head and no prosthetic arm on his right. 

But it’s easy to know when Keith’s staring, gaze heavier than anything Shiro has ever endured. And he has, without any shame. Shiro has managed to avoid eye contact most of the time to keep some semblance of control of the situation, but when he doesn’t, he’s brought to silence at the intensity in Keith’s gaze, bright with quiet admiration but with something dark at the back Shiro is unwilling to name.

Shiro didn’t think it’d get worse, but then he’s making a nerd joke in the middle of the class and Keith is the only one that laughs, snorting uglily and prettily and making Shiro’s heart flutter uncontrollably.

“I don’t get what the problem is here.”

Shiro grumbles into his beer, the buzz from it not making the tug on his heart better.

“That he’s just-” he gestures, trying to capture the beauty of who Keith is with sluggish movements, caused by the alcohol and his full-blown crush, “And I can’t forget him. He’s so smart and witty and laughs at every single one of my jokes-”

“Wow, marry the guy.” Matt’s sarcasm is sharp, but Shiro whines, wishing he could propose to him next Monday. “Just ask him out, Shiro.”

“I can’t,” Shiro whimpers, eyes wet from frustration. “He’s my student. I can’t fraternize with my students. If they find out, I could lose my job.”

Matt just hums into his beer, half listening to Shiro’s melodrama. “Who says they have to find out?”

And Shiro hasn’t entertained the idea of bending a rule for a while, not to a hair before its breaking point. It's dangerous and stupid and wrong.

But he closes his eyes and Keith is there, biting on his lip as he goes deep in thought, leaning his cheek on his palm, fluttering his eyelashes when Shiro meets his gaze, tilting his head in consideration and smiling in a way that makes Shiro ashamed of his thoughts.

And the words stick.

“What are you doing here?”

Keith looks up from his phone, lollipop tucked in his mouth, lips puckered up. He shouldn’t look so good in gym leggings and a huge shirt that swallows him whole, but he does. He pops the candy out as he eyes Shiro in the middle of the hallway, and Shiro burns.

“Waiting for you,” he says as if it’s not a big deal, head tilting towards Shiro’s office, “Thought you could help me out with the final paper.”

“You’re the best in the class,” Shiro remarks, not moving from the middle of the hallway, far enough to keep a sane distance between them. “I don’t think you need any of my help.”

Keith shrugs, a glint on his eye and a crook on his smile telling Shiro that he knows — Keith isn’t here because of the final paper.

“Make me worth my while.”

And Shiro shouldn’t.

He really shouldn’t.

He’s been sleep-deprived enough to have no control on his body, and having Keith in the shoebox the university pretends it’s an office for the TAs is a bad idea. But sleep-deprived means Shiro’s self-preservation is near to nonexistent and his desire over-rules his sense of danger.

“Come on in.”

It’s not the first time Keith has been in his office, but it’s the first time it’s been after hours. It’s always been with other people milling around, students knocking on Shiro’s open door to ask for something quick or pick up a paper. But today it seems everyone has plans, and the whole wing is deserted aside from the security guard at the front door and a couple of administrators. Shiro knows it’s because of the midterms, and he really wishes Keith wasn’t as smart as he really is so he could be stress-studying instead of walking into Shiro’s office on a Thursday evening when the building is almost empty.

It’s also the first time Shiro’s office door is closed, pulled into the latch by Keith’s hand.

“What can I do for you?” Shiro asks, trying and failing to notice the click the lock does. 

But Keith doesn’t answer, lingering at the door. There’s a thoughtful look in his eyes, and Shiro feels like a bug under a magnifying glass.

“Keith?”

Keith smiles at him then, all innocent-pretending as he slowly crosses the office and to the chair in front of the desk. Except he doesn’t sit, curiously looking over the shelfs along the walls. It makes him turn his back to Shiro and Shiro can’t help but follow Keith’s hands tucking at the small of his back, gaze inevitably sliding down the curve of his ass, visible under the bunched hem of the giant shirt.

Shiro clears his throat, looking away. “Keith?”

Keith hums, looking over his shoulder. “What?”

His tone is light, almost playful, and Shiro is torn between loving it and hating it.

“What can I do for you?” Shiro asks again and Keith’s smile ticks up.

“I just have a couple of questions.”

Shiro watches him — the tilt of his body, the lazy curve of his neck, the smile turned smirk.

Who says they have to find out?

“I was wondering,” Keith starts, taking a tentative step around Shiro’s desk and sliding his fingers over the papers over it, “if I’ve been imagining it.”

Shiro takes a steadying breath, gut burning from how close Keith is getting, as close as he’s never been. They’re not close enough to touch by mistake, but Shiro has the urge to reach out. “What?”

His voice is a low rumble and Keith pauses, a visible shiver going up his spine.

“The way you look at me,” he mutters darkly, stepping closer.

He’s a breath from standing between Shiro’s spread knees, a confidence Shiro has seen more often during class growing stronger in the way he holds himself right now. It makes it harder to breath, to keep his hands to himself and not find out how Keith’s leggings would feel against his palms, how his thighs would move if Shiro was to squeeze them, how soft the oversized shirt would feel like if pushes it away to find place on Keith’s bare and tiny waist.

He’s incredibly attractive and Shiro is going insane.

“Is it real?”

Shiro gulps. This is bad.

“I don’t know what you’re talking about,” Shiro lies, and as every time he has lied in his life, it falls flat.

“Right,” Keith chuckles, the lovely vibration coming from his chest making Shiro’s stomach flutter.

“What do you want from me?” Shiro asks quietly — pleads, really. He doesn’t have enough control of himself to not do something stupid. He needs Keith to say no to avoid that. He needs Keith to step away and walk out and not see Shiro the way he’s seeing him right now, with a desire Shiro feels growing and drowning everything in its path.

“Actually,” Keith mutters, stepping into the V of Shiro’s thighs, “That’s what I was going to ask you next.”

A sound of surprise startles out of Shiro when Keith lifts one of his knees, sliding it up Shiro’s thigh and down to the little space there is between the armrest and his leg. It’s the first time they’ve touched, and Shiro is burning from the point of contact, heart wild in his chest.

“Yeah?” Keith asks as Shiro’s gaze trails from his knee leaning unto the chair, to the strong thigh under dark leggings, to the baggy shirt and to Keith’s smug expression.

“I-” Shiro chokes, hands flexing to keep them in place and not to reach out to Keith’s legs, to the hips he keeps hidden beneath the large shirt that looks suspiciously similar to Shiro’s shirt size and Shiro can’t help but imagine it’s his, falling loose from Keith’s shoulders and showing how tiny he is. “Keith-”

“Yes, Professor?” Keith whispers, amused, pushing his knee closer to Shiro’s hip.

“I’m not a professor,” Shiro grits out, hand moving before he can think to grip Keith’s thigh to keep it still. His self-control fray further at the give in Keith’s muscle, fingers digging before he can take control of himself. “Keith- I can’t.”

Keith tilts his head, looking Shiro up and down. He knows how he looks, hot and bothered as he feels, but this isn’t okay.

“You don’t want to?” Keith asks, tone serious. He has also pulled away to give Shiro some space, but since Shiro doesn’t let go of his leg, he doesn’t get out of his lap.

“I want,” Shiro confesses, maybe too eagerly, not keeping his hand from kneading into Keith’s thigh, marveled by the strength in it. He wants to be crushed between them. “But I can’t.”

“Why not?” Keith all but pouts, pretty pink lips still shiny from the lollipop he threw away at the trash can at Shiro’s door, “We’re two consenting adults, aren’t we?”

“You’re my student,” Shiro breathes, fingers cramping around Keith’s thigh to stop himself from squeezing again. “It’s against the rules.”

Keith hums, as if considering. For a second Shiro thinks he’ll leave it like that. That he’ll pull away and apologize before walking out of the office and avoid any further contact with Shiro for the rest of the school year. It makes Shiro’s heart wither and he barely has time to resent it when Keith’s hand is suddenly placed on his shoulder and makes him flinch, not expecting more contact.

“Good, then,” Keith announces as he uses his leverage on Shiro to completely straddle his lap. “I love breaking rules.”

Shiro’s protest dies down on Keith’s lips, pillowing against his mouth. They’re soft, slightly sticky and sweet from the candy, and Shiro groans, letting himself loose and shyly kissing back. He can feel Keith’s smile curve in the kiss, but it doesn’t last long, instead opening a sliver and licking over Shiro’s upper lip. A shiver climbs up Shiro’s spine and he forces himself to pull away, panting from how lightheaded Keith makes him feel with just his weight on his lap and a kiss bordering filthy.

“K-keith,” he tries, hanging his head back to look up at Keith, taller on his knees on either side of Shiro’s legs, “I- We shouldn’t-”

Keith’s nose wrinkles prettily and Shiro’s breath hitches at the rough fingertip tracing reverently his lower lip, Keith’s attention completely taken by the give in the soft meat.

“Why not?” Keith asks, sounding genuinely curious, “Are you seriously worried about dumb rules?”

“I could get fired,” Shiro blurts out, voice high-pitched in panic that washes away the arousal like a stormy tide. The anxiety is already prickling his palm and Keith must catch it, as how his face sobers up carefully watching him. “I can’t get fired, Keith. I don’t want to go back to serving coffee and barely have time to work on my thesis. If someone finds out-”

“No one has to.”

Shiro pauses, mouthing around the words that push to tumble out in a frantic ramble. He should be embarrassed, but the way Keith takes what he said seriously makes a weight lift off his chest.

“No one has to find out,” Keith says again, leaning closer and sliding his hand down to Shiro’s chest, “No one will. I swear. I just-”

He cuts himself off, biting his lower lip, and Shiro stares at it for a long while, wishing he could do the same, wishing he could’ve met Keith in a different situation and their relationship as teacher-student never would’ve existed. He believes he would’ve fallen for him in any other circumstance, first drawn by his beauty and eventually fall for him.

“I can’t stop thinking about you.”

It’s Keith who says it, a pretty red color spreading across his face and reaching up the tips of his ears, barely visible under his black hair but completely on sight from where Shiro is sitting beneath him.

“And I... I know I should’ve waited until after finals,” Keith continues quietly, eyes fleeting away from Shiro’s wide ones, “But it’s been so hard. I see you at least thrice a week and you’re so hot, and you’re always so attentive and sweet- You're so fucking sweet I can’t believe it.”

“Sweet?” Shiro asks before he can stop himself, insecurities flapping around at being called hot. “Me?”

Keith raises a shoulder, abashed. “You don’t treat me different from your other students. You even defended me from Griffin that time and told me I did a good job.”

Oh, Shiro thinks, and then says, “You deserve the same opportunities as them.”

“That’s what I’m talking about,” Keith chuckles weakly, eyes bright. “How am I supposed to get over you if you’re so perfect?”

He kisses him again, more collected and impossibly sweeter, even with the taste of the candy gone.

“No one has to find out,” Keith says again, now into Shiro’s lips. “No one will. I swear.”

Matt’s voice echoes at the back of his mind, but Shiro doesn’t pay him half a mind, brain fizzled out at the little whine on Keith’s voice, self-control finally ripping in half.

“You’d have to be quiet.”

The words are out before Shiro can realize he’s said them and he can’t get an ounce of regret or shame when Keith’s cheeks darken in a beautiful blush, eyes glinting.

“I’ll be quiet,” Keith promises, eager and earnest. “Not a peep. Just- Please.”

Arousal parks to life in his gut once again at the little plead, chest rumbling as he hums, contemplative. “I won’t go easy on you.”

A shudder rattles Keith’s frame, hands grasping Shiro’s shoulder for dear life. Shiro is quick to do the same to his hips, keeping him on his lap, indulging in the muscle he can feel under the movement of his thumb.

“You don’t have to.”

It’s easy to pull him then, to let him sit his weight entirely on his thighs. Shiro nuzzles Keith’s cheek, a gasp falling on his mouth, and he kisses him, slow and purposeful, how he had wanted to ever since the beginning of the semester. Keith opens his lips for Shiro to lick into, all soft and pliant under Shiro’s patient ministrations, but there’s an edge of desperation in every motion back from Keith, one that grows noticeable with the barely-there roll of his hips.

Shiro pulls away, glancing down at where Keith is hard under his thin leggings, shirt rumpled up from his lap. Shiro is hard, but the thick fabric of his jeans gives him modesty.

“How do you want it?” He asks, meeting Keith’s heavy-lidded eyes, shocked at the confidence growing in him. “Tell me.”

Keith flusters, blinking down at Shiro in pleased surprise. “I-I-” He exhales heavily, rocking his hips. “I want you. Inside me.”

“Good,” Shiro says, basking in the delight shown in Keith’s expression, and slides his hand down to Keith’s ass, squeezing gently before frowning at the faint dents under the soft fabric. “What’s this?”

Keith chuckles, breathless and eager, and he pulls his hands away from Shiro to lift the hem of his shirt. “I- At first I thought I’d have to seduce you or something.”

Shiro’s brow furrows more, confused as to why Keith would need to try to seduce him when he’s already heads over heels for him, but the question dies down on his throat with a groan when Keith bunches the shirt all the way to his armpits and reveals red lace over his chest. Thin bands criss-cross around Keith’s pecs, framing the dusty nipples under the flowery lace. Shiro’s mouth waters, urging him to lick over the bralette and feel the texture of the mesh on his tongue, searching for the nub underneath.

“Surprise?” Keith whispers, voice shaky in doubt when Shiro just stares, and Shiro snaps his eyes up to meet Keith’s, “Do you like it?”

“Get off.”

Keith frowns. “What?”

“Off. Now.”

He doesn’t wait for Keith to move, pushing him off his lap as he stands and making him turn, instead bending him over the desk. Keith goes with a yelp, staggering and managing to avoid knocking his legs with the edge.

“A-ah, P-professor,” Keith stammers, looking at Shiro over his shoulder and attempting to upright. But Shiro is quick to put his prosthetic hand at his upper back, heavily keeping him there, “What-”

“Shiro,” Shiro corrects, letting his other hand spread over Keith’s bare spine, pushing the shirt up until he can see the brooch of the bralette, the thin bands going up Keith’s shoulders and meeting between his shoulder blades. He traces them, fascinated by the softness of it, by the warmth coming from Keith’s skin. “Is this for me?”

Keith twitches as Shiro slips the tips of his fingers between his back and the bralette.

“Yeah,” he breathes, swaying his hips a little, “You like it?”

“Like it?” Shiro parrots, smoothing his fingers down Keith’s back, eyes following the motion. He stops at the hem of his leggings, hugging his waist, and Keith shudders slightly. “Is it a set?”

Keith bites down on his smile, and that’s the only answer Shiro needs to peel them off, breath hitching at the flowers of lace covering half of each of Keith’s ass cheeks, thin bands going around his sharp hips.

“Fuck,” Shiro groans, and can’t help but press his clothed erection to the mess between Keith’s butt, “Holy shit. How are you real?”

Keith laughs, the confidence in his voice making Shiro’s chest burn. “Gonna do something about it, Prof- Shiro?”

He wiggles his hips, enticing, and Shiro takes a steadying breath, one big enough to make his lungs hurt.

“I don’t have any lube,” Shiro informs him, thumbing over the lace before pushing it aside.

“Good thing I came prepared.”

His fingertip meets wet skin and Shiro swallows down a growl.

“You prepared yourself,” Shiro whispers, spreading Keith’s ass and staring right at his hole, soft and loose as he presses the pad of his thumb against it.

“I was feeling lucky.”

Shiro hums, tapping it while he uses his other hand to unbuckle his jeans. He pauses for a moment before pulling down his boxers, frowning.

“I don’t have a condom.”

Keith grumbles. “Do I have to do everything, old man?”

He lifts one of his feet from the floor, sneaking his forefinger by the side of his boot, and pulls out a condom that Atlas U’s health department sometimes gives away for free.

“Give that.” Shiro snatches the package a bit too desperately, winning a rumbling laugh from Keith, and rips it open one-handed as he pulls himself out with his other hand.

Keith arches his spine a little to look over his shoulder, gasping. “Oh, wow.”

“What?” Shiro asks after he’s put on the condom and Keith hasn’t said anything else.

But there’s no need for Keith to say something, gaze dark with want as he eyes Shiro’s dick appreciatively. Shiro knows he’s bigger than average, but it didn’t matter to him until right this second, with Keith watching it with so much desire Shiro feels about to burst already.

“You ready?”

Keith wordlessly spreads his legs further and sways his hips. “Do your worst, Professor.”

Shiro doesn’t correct him again, noticing the inch of teasing in Keith’s tone, and takes a steadying breath as he rounds his palm over the side of Keith’s waist and taps the head of his cock over his hole, balls twitching. “Fuck.”

“Yeah?” Keith asks, breathless, and a whine falls from his lips when Shiro pushes in, as slow as he can manage, “Oh, fuck-”

“You’re so hot,” Shiro pants, body overheating with Keith gripping him like a vice. He’s prepped, yes, but it’s still a tight fit. “So fucking tight.”

“B-big,” Keith stutters, “I- God- So big.”

“But you’re going to take it, right?” Shiro asks, pausing halfway in and pulling out until only the head is inside. Keith whimpers, hands scrambling for leverage as Shiro fucks into him again, and knocks down a few papers that didn’t fall when Shiro pushed him into the desk. Shiro doesn’t care for them, though. “You’re taking it good, aren’t you?”

“Fuck-” Keith gasps, shuddering all over, “You’re- Are you- Tell me you’re in.”

“Halfway through, spitfire.” Shiro pauses again, giving Keith time. He indulges a little and traces the puffy rim stretched around his dick, and slowly rolls his hips, dragging inside until he’s flush to Keith’s backside. Keith flinches, rattling the desk, and Shiro drapes over him to keep him still. “You’re doing so good, Keith. Breathe for me.”

Keith does, shuddering in and out, but he repeats the process until the trembles subside slowly.

“There you go,” Shiro whispers, grazing his lips over the arch of Keith’s red ear, “Good job.”

Keith twitches again, a moan falling from his open mouth, and Shiro shushes him, gently grinding into him.

“You promised me to be quiet, sweetheart,” Shiro reminds him quietly, watching Keith’s jaw flex closed to keep the sounds in. “You sound gorgeous. But we don’t want to get caught.”

“S-shiro,” Keith whines through clenched teeth, “M-move, please.”

Shiro smiles against his skin and takes his time to pull back. The drag is delicious, clouding up Shiro’s head, and he can’t stop himself from thrusting in sharply. A high-pitched sound dies down in Keith’s throat as he slaps a hand over his own mouth, eyes tightly closed.

“Like that?” Shiro asks, doing the same thing and making Keith’s whole frame quake under his weight. “You like it, hotshot?”

Keith nods, hair in disarray around his face, and Shiro sighs, delighted. He keeps that rhythm for a while, steadily going faster, and Keith literally melts on his desk, hand still on his mouth to mute his moans but otherwise pliant under Shiro’s thrusts. There's something inherently hot to have bent Keith over his desk and to be fucking him like this, with the crimson lingerie adorning his skin and with the dangerous possibility of getting caught. But even when it’s hot for Keith to be muting his moans by his request and for anyone — literally anyone to be walking outside his door, unassuming of what Shiro is doing to one of his students, Shiro thinks it's not enough.

He wants to see Keith’s face, to watch him fall apart. He wants to hear every one of his whines and moans, but he can’t have that. Not here. Not yet.

He stops for a second to pull out, Keith making a confused sound that chokes into surprise when Shiro turns him over the desk, propping one of Keith’s legs over his shoulder as he pulls the other free of the leggings.

“Look at you,” Shiro says, eyes fixed on Keith’s weeping cock, still trapped in the very wet lace of the panties. “So beautiful.”

Keith arches his back, hair clouding around his flushed face, and Shiro threads his fingers through it, confirming the softness of the strands.

“Inside,” Keith rasps out, weakly reaching for Shiro, “Please-”

“Okay, gorgeous.”

It’s easier to push in this time, but no less devastating. Keith flutters around him with every drag, more sensitive than he was before, and Shiro feels so fucking close. He leans down to kiss him on the mouth and down his neck, sucking at the thin skin. Keith buckles, whining, and Shiro pants.

He wants to come, he wants-

“Profesor Shirogane?”

Shiro freezes, feeling Keith flinch, and both look towards the closed door, the knocks they didn’t hear at first getting louder.

“Are you in there?”

Shiro meets Keith’s panicked eyes, watching him mouth, ‘Griffin?’ in shock. They stay motionless for a long moment, but soon the alarm washes down and Shiro can’t keep his hips still. He tentatively drags back, Keith shuddering and hand falling on his mouth to keep quiet. And when Shiro meets Keith’s gaze, wordlessly asking, Keith nods, eyes dark in desire.

James knocks again when Shiro thrusts in slowly, adrenaline rushing through his blood, and he doesn’t care for one second as he keeps thrusting into Keith, slow enough to not clatter the desk but deep enough to make Keith’s eyes roll to the back of his skull.

“Professor?” James insists, “I just have a few questions about next week’s test.”

And fuck, Shiro has never hated someone so much as he does this little bastard.

He takes a deep breath to keep from biting out a go the fuck away, and instead buries his face in the crook of Keith’s neck.

“I’m close,” he mutters into it, feeling Keith shiver, “Can you stay quiet?”

Keith nods, a little too vehemently, and Shiro continues fucking into him, slow and steady. Keith spasms around him, hips shaking to take more of Shiro, but Shiro grips the edge of the desk to keep it from creaking.

“Shiro?” James asks, knocking yet again, and Shiro inhales deeply, finding comfort in Keith’s earthy scent.

The pleasure tightens in his gut and his ears buzz from the rush. He chases the feeling, drunk in Keith, and soon his thrusts stagger, pushing in one last time before his dick throbs. He shudders, the orgasm hitting him like a freight train, and Keith’s breath hitches, nails raking over Shiro’s shoulders, shirt almost ripping in their wake.

His knees feel weak when he tries to push himself away from Keith, to give him some space to breathe, but he pauses halfway when he sees Keith’s heaving chest, bralette straining with every breath. His gaze travels down his torso, to his still-hard erection, and while he wishes he could admire it without an orgasm-cottoned head, he stares at it long enough to commit it to memory. The head is painfully red, almost bordering purple under the lace, and the extension is mouth-watering, slightly curved to the left and tucked to the jut of his hip bone.

Shiro slowly frees it from the panties, a moan escaping Keith’s bitten-red lips before he can bring his mouth to cover them.

“He’s gone,” Shiro says, although he can’t know for sure. Keith blinks up at him, brow heavy over his eyes, and slowly uncovers his mouth. “You haven’t...”

Keith grunts quietly, squirming, and Shiro hisses when he squeezes his cock, still buried inside of him.

“Touch yourself.”

Keith looks disoriented, eyes dazed, but still brings a hand to his dick, delicately circling it. Shiro watches as he flicks his wrist weakly, hips twitching to follow the motion, and Keith bites on his lip, stifling the sounds that rumble on his chest.

“Yeah, sweetie.” Shiro stares in a daze, feeling every pulse of pleasure from Keith whenever he squeezes the cockhead, a gasp falling from his open mouth. “Come for me.”

Keith throbs around him, shivering all over, and Shiro grunts in overstimulation as Keith’s cock kicks and spurts messily over his stomach, catching on the mesh of the bralette.

“Fuck,” Shiro gushes out, feeling his own dick twitch.

Keith blinks a few times, fluttering away the sparks of the orgasm, and he locks gazes with Shiro, shockingly grounding.

“Hey,” he exhales, lips curving in a smile, and wow, Keith is so pretty.

“Hey,” Shiro says back, already dizzy with the tight hold on his steadily softening dick. “I’ll… uh…”

He gestures to their hips and Keith chuckles breathlessly, nodding. Shiro pulls out, the drag very much intoxicating, and Keith gasps quietly when he pops out.

“Fuck,” Keith curses, bringing his clean hand to the trail of hair under his navel. “You filled me up good.”

Shiro grimaces, pulling off the full condom and checking it’s not broken. “I didn’t?”

Keith cranes his neck to see the tied up condom and snorts. “I meant your dick. You have a mean dick, Shiro.”

Shiro chokes, having to clear his throat before he takes a few tissues from the box on his desk and wrapping the condom in it. “R-right.”

Keith stays silent, watching him like a hawk while he puts himself inside his jeans again and walks on shaky legs to the door to throw away the condom.

“I wouldn't mind you coming inside next time.”

Shiro trips on his feet and turns to gape at Keith, still lazily draped over his desk, head tilt to a side and leaving his hair out of the way for his body to be entirely visible. He hasn’t even tried to pull on his shirt, giving Shiro a knowing smile.

“Y-you,” Shiro grits out, head hazy with the idea, “can’t say that.”

“Why not?” Keith’s smile crooks on one side, “It was good.”

And yes. It was. It was so good Shiro could die. But Shiro can’t let this happen again. It was a moment of weakness, one that threatens to pull him in all over again as Keith stands from the desk to fix his clothes and hair.

“This was a mistake,” Shiro blurts out, to what Keith pauses, looking over his shoulder. “I can’t date students.”

Keith frowns, giving Shiro a careful look, and pulls his hair up in a bun that burns a hole in Shiro’s chest.

“Date?” Keith repeats, thoughtful, and Shiro feels he messed up.

Of course Keith wouldn’t be interested in Shiro in a serious way. Of course he just wanted a fuck, maybe just for the thrill of breaking a rule. Not because he liked Shiro. Because Shiro is un-likable.

“Uh-”

“What about ex-students?” 

Shiro startles, shocked to see Keith has walked all the way to him, grinning up at him with cheeks flushed and a spark in his blue eyes.

“What?”

“The semester is ending soon.” Keith shrugs, “I thought you’d be interested in having a drink with me once it’s over.”

Shiro stares, unbelieving. “Really?”

Keith’s smile falters, and he looks away. “Well, yeah? If you want? I know you’re like, super out of my league, but-”

“I- What.” Shiro squeaks, hysterical, “Are you serious?”

Keith hunches, lips puckered in an embarrassed pout. And it shouldn’t be endearing and cute and terribly innocent, not after what they’ve done in the last half hour and knowing what Keith is wearing beneath his clothes, probably sticky with his own come.

“Keith,” Shiro says, quiet and eager, face burning from expectancy, “Do you like me?”

“Yeah?” Keith mumbles, “I mean, I just had sex with you, so-”

“No.” Shiro steps closer, reaching for Keith’s fidgeting hand, playing with the hem of his shirt. “I meant- Do you like me for real?”

“‘For real’?” He scoffs. “What are you, a kindergartener?”

Shiro chuckles. “I’m actually 7, thank you very much.”

Keith rolls his eyes, but it’s more fond than anything else. “Right. Leap year.”

“I’m just shocked,” Shiro confesses, to what Keith sobers up immediately, “You seriously want to date me.”

Keith grins, all sharp and witty and gorgeous. “When we’re free men, that is.”

“It’s worth it,” Shiro hums, eyes flickering down to Keith’s curved lips. Keith bites them, knowing, and Shiro sighs. “Can I…”

“I won’t stop you, darling.”

Shiro kisses him, loving the petname, and Keith lets him settle the pace, slow and sweet.

And rather than an end, it feels like a glorious beginning.