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They shouldn’t be doing this.
Giyuu braces one hand against the back of the driver’s seat, his other is gripping weakly at Sanemi’s upper arm. He can feel the sweat-slicked skin beneath his trembling fingers, can feel the way the muscle tenses when he digs his nails into the taut flesh. A particularly hard scratch draws a growl out of the depths of Sanemi’s throat, and he makes it his mission to fuck Giyuu even harder into the cramped backseat of his car.
They really shouldn’t be doing this.
They’re both half-dressed. Sanemi’s slacks are still mostly on, but the button and zipper have been undone just enough for him to free his aching cock. He’s still wearing his shirt, too, but it’s no longer tucked in and most of the buttons have been opened, revealing his bare chest to the heat of the car.
His sleeves are hitched up to his elbows, and Giyuu can feel the creased fabric sticking to the underside of his knee where Sanemi has his leg hooked on his arm. Giyuu’s other leg is thrown over his shoulder, but their position has it pressed to his chest, testing every single limit of his physical flexibility, some of which was entirely non-existent before now. Sanemi doesn’t seem to care.
He fucks like he talks; rough and without restraint.
If it weren’t for the old hoodie folded haphazardly behind Giyuu’s head, he’s certain Sanemi would’ve fucked him right through the closed car door. His pace is unrelenting, like he’s completely dedicated to carving out a space inside of his colleague just for his cock. The thought makes Giyuu whine, loud and absolutely mortifying, but the sound spreads a wicked grin across Sanemi’s face.
They both know that they absolutely should not be doing this. But whether or not they can stop is an entirely different story.
It’s getting late, it’s dark outside. Sanemi’s car is parked in his reserved spot at the high school in which they both teach. All students have long since gone home, but Giyuu knows that most of the teachers are still around. At first, they’d both been committed to their silence to avoid being caught, but such a caution had long since been forgotten.
“Jesus - fuck - Tomioka.” Sanemi speaks in time with his thrusts, each snap of his hips punctuating his words. Giyuu’s name spills off of his tongue like some filthy swear word. He absolutely loves it. “No matter how many times I fuck you, you’re still so damn tight.”
Sanemi pulls all the way out, pausing for just a split second before he slams back in. The force pushes Giyuu forward a few centimetres, and a high-pitched moan ( Shinazu-- nemi! ) is ripped from his chest at the exact same time.
Giyuu scrambles for something to grab onto. The back of the car seat provides him with nothing, so he settles for gripping tightly at Sanemi’s upper arm. He can tell it hurts, sees the way the math teacher’s face contorts in some form of pain before that devilish smile is present once again.
Leaning over Giyuu, forcing his leg to stretch even further, Sanemi buries his face in the crook of his sweaty neck and sinks his teeth into the pale skin. It’s already littered with bite marks and bruises, a reminder of what they’ve done (what they shouldn’t be doing) and it’s something Giyuu will have to cover up tomorrow, but he can’t bring himself to think of doing that right now.
He loves it when Sanemi marks him up, tells him it’s because he’s his. They’re not together, they just have sex, but Giyuu’s heart does an undeniable little flutter whenever Sanemi claims him like that. When he grabs a fistful of his hair and fucks him into his mattress, or when he shoves his cock down his throat until he cries. My little slut. He can be so degrading with his nicknames.
Giyuu loves that, too.
Sanemi scrapes his teeth over the mark he’s just made, smirking against his colleague’s skin. Giyuu can feel it, the twitch of his lips as he admires his handiwork.
“Look so pretty when you’re covered in bruises,” he mumbles, and for a moment, his pace slows. Sanemi let’s Giyuu’s leg slide from over his shoulder down to the crease of his arm and he sits back. His lower lip is caught between his teeth now, and he stares down at Giyuu with something unidentifiable dancing around in his eyes as he rolls his hips.
The gym teacher forces his eyes open (when had he even closed them?) and stares back at Sanemi, drinks up the dazed look on his flushed face. His hair is even more of a mess than usual, glued to his forehead with sweat in some places and sticking up like he’s been electrocuted in others. There’s a certain hunger etched into his features, something Giyuu has seen in him before. He lets out a pitiful little mewl, and like a firework, Sanemi is ignited once again.
Using his hands to grip the other by the knees, Sanemi leans over to him and the speed of his thrusts picks up again.
“Such a little whore,” he spits. The slapping of skin against skin is so loud, it’s almost hard to hear him. “You just want it fucking rough, don’t you, Tomioka? You don’t want me to take it slow with you, all you think about is getting fucked so hard you can’t walk.”
Giyuu’s little whimpers turn into much louder whines in just a split second. Sanemi is pushing his legs further apart, and even just the slight change in angle has him hammering into his prostate over and over again. He lets go of Sanemi’s bicep and pulls his hand away from the driver’s seat, folding both arms over his face. The heat of his cheeks against the skin of his forearms is mortifying. Giyuu can only imagine how absolutely fucked he looks.
“No use hiding your face, Pretty Boy,” Sanemi growls, forcing Giyuu’s legs apart even further and absolutely relishing in the moan that it elicits. “You like it when I call you names, don’t you? You fucking - love - when I remind you of how much of a little bitch you are when it comes to my cock.”
Sanemi has a filthy mouth, in and out of sex. Giyuu would be a liar if he said it didn’t turn him on.
He opens his mouth to speak, a weak mumble in his own defense, but Sanemi fucks into him again and anything he might’ve said is instantaneously reduced to a few incomprehensible little squeaks that soon get lost in the midst of a heated kiss.
It’s hot and sloppy and wet and their teeth keep clashing in the worst way possible, but Giyuu drinks up the taste of Sanemi’s mouth like it’s the last thing he’ll ever do on earth. There’s a string of saliva trickling down his chin and Giyuu doesn’t know if it’s his or Sanemi’s or a concoction of both, but whatever the answer may be, he really doesn’t care.
Sanemi tests the waters and pushes his legs closer to his chest. Now, Giyuu’s knees are close to knocking into his shoulders. Sanemi is bent over him, pressing messy, open-mouthed kisses over every inch of exposed skin he can get to. There are so many sensations dancing on his skin, Giyuu thinks he’s going to go crazy.
“How’re you holding up, Princess?” Sanemi growls, his voice low and mixed with something animalistic that makes Giyuu whine. “You gonna come for me?”
He snaps his hips forward again, drilling the head of his cock directly into Giyuu’s prostate and sending him another few centimetres up the seat. The coil in his abdomen tightens just that bit more, toned muscles tensing in anticipation.
“P- Please,” he pants, arching up off of the car seat and leaning his head back, exposing the column of his pale throat. Sanemi leans down and scrapes his teeth over Giyuu’s adam’s apple, letting out a low moan of his own when a shrill and high-pitched “‘Nemi!” escapes the trembling mouth of the man beneath him.
“Please what, baby?” he asks, and even his voice is faltering now. His thrusts are less calculated and much more erratic, hips stuttering every time Giyuu clenches down around his cock.
The gym teacher peeks out from under his arms. His legs are shaking in Sanemi’s hold, his body aching for release. His cock is hard against his stomach, leaking all over the sweaty skin. Untouched, as per usual. Sanemi’s ego likes the high of making Giyuu come without playing with his dick.
He seems to sense that he’s going to ask for that to change, because yet another smirk is plastered across Sanemi’s face and he forces his hips to still mid-thrust. Giyuu lets out a sob, desperately trying to buck back against him, trying to slide the last few inches of his cock back inside.
Sanemi smacks him.
It’s hard; a rough slap to the outside of his thigh that tears another sob out of the depths of Giyuu’s throat and forces him to stop moving. His cock twitches in interest as a red handprint blossoms over the milky white skin of his leg.
“You want me to touch you?” he asks. Giyuu nods, and Sanemi lets out a snort of laughter. It’s mean. He loves it. “Not a fucking chance, Pretty Boy. You come on my cock or you don’t fucking come at all.”
The way Sanemi can switch in the blink of an eye from calling him a slut to calling him a pretty boy always gives Giyuu butterflies. Even when those pale purple eyes glare into his soul, he can’t help but feel all floaty on the inside. His head gets.. fuzzy.
Sanemi smacks him again and it pulls Giyuu out of his trance so abruptly, he’s genuinely stunned for a few seconds. When he realises what happened, a delayed whine slides off of his tongue. There’s another handprint forming on his other thigh, angry and red against his pale skin.
It’s another mark from Sanemi; he can’t help but love it.
In the blink of an eye, the math teacher builds his pace up again. He plows into Giyuu, no concern whatsoever for the fact that his colleague is nowhere near as flexible as this position requires him to be.
Mumbles of how pretty Giyuu is intermingled with insults hurled at how dazed and submissive he looks right now are lost in the hot and heavy air between them. The smack of Sanemi’s hips against his own is bruising, as is the grip he has on Giyuu’s knees. The coil in his abdomen tightens again.
“Shinazu-- Sanemi, please, I’m- I’m g-.. mmph !”
Giyuu is cut off by another kiss, but this one is nowhere near as vicious as the first. Despite the fact that Sanemi is fucking into him so relentlessly, the movement of his lips is soft. He swallows all of Giyuu’s moans and whines and when he finally comes, he just barely bites down on his swollen and spit-slicked bottom lip, eliciting the prettiest of post-ejaculatory sobs from the man underneath him.
Sanemi’s orgasm hits him almost immediately afterwards, and he spills into the condom with a low and drawn out groan of Giyuu’s name spoken against his parted lips.
In the moments that follow, Sanemi pulls out. In complete contrast to how he was just minutes ago, it’s gentle. He lets Giyuu’s legs down carefully and leans over him to press a loving little kiss to his forehead.
They’re not together, they just have sex.
But Sanemi never forgets about aftercare.
“How are you feeling?” he whispers, reaching up to brush Giyuu’s sweaty bangs off of his face. The careful glide of his calloused fingers over his sweaty skin makes the gym teacher smile a little. He’s still a little out of it after everything they’ve done, but that reaction paired with his mumbled “‘m good” reassures Sanemi enough for his shoulders to slump in relaxation.
The clean up is quiet, but it’s nice like that. Giyuu is content to just lay there while Sanemi helps fix him back up, oh-so gentle and smooth with every single one of his tentative touches. He wipes the drying come from his skin and presses apologetic kisses to every single bite mark that’s left as a reminder of what they’ve done. As he zips Giyuu’s pants back up for him, he leans down to give one of those kisses to his mouth, too.
“You did so good,” he says, pecking at the corner of his lips and then his jaw, all the way down to the first bruise he sucked onto his neck. “Such a good boy. Thank you, Tomioka.”
Sanemi drives him home after that, stops at the store on the way to pick up a carton of chocolate milk because it’s one of Giyuu’s favourites. Sometimes, he shows his care in the most subtle of ways, but that works well for both of them. They’re not together, after all, and they really shouldn’t have done what they just did.. but who the fuck cares?
They say their goodbyes after Sanemi pulls up outside of Giyuu’s apartment block. If he walks him to the door and they share another sweet kiss outside before they part ways, nobody has to know.
---
The next day, Sanemi shoots Giyuu a look at the coffee maker in the staff room. It’s an “ are you okay?” kind of look that makes the gym teacher’s chest tighten. He gives a nod of reassurance and opens his mouth to speak, but someone behind him beats him to it.
“You two really ought to learn to wait until you get home to get it on,” Obanai says, squeezing his tiny body between them to take his own turn at brewing a mug of coffee. Sanemi and Giyuu share another look over his head, one lacking all the softness they’d shared not a minute prior.
This one screams “oh, shit.”
When he receives no answer, Obanai stands back and looks up at them both. “Unfortunately for me, I can’t request a new parking spot, so I’m stuck next to Shinazugawa for the foreseeable future.” He folds his arms over his chest. “I’d really appreciate if I didn’t have to listen to you two fucking.”
Another silence falls over them, and the chemistry teacher rolls his eyes, snatching up his cup and turning on his heel. “Stop staring at me like you don’t know what I’m talking about, and keep it in your pants next time,” he mutters, before storming off to join Kanroji at the table on the far side of the room.
Sanemi looks at Giyuu, and Giyuu looks back at Sanemi. The quiet stretches on for what feels like several minutes, until finally, the gym teacher cracks a sheepish smile.
“My car next time?”