“Fuck, Derek, oh my god.”
What had started as chicken-footsie under the table at the back of the library as they researched the latest big nasty had, unsurprisingly, turned into whatever this now is.
Derek’s sucking on his neck and Stiles can barely keep his voice down as he swears at the pleasure-pain. There may be blunt human teeth involved. He’s going to have such a hickey when this is over. He’s not sure he cares because Derek’s really fucking good at this.
They’ve been fucking semi-regularly since he turned 18, and always in Derek’s bed, back at his loft apartment. But this is new. This is apparently a kink Stiles hadn’t known he harbored.
Derek crowds him up against the wall behind the last stack of shelves, there’s no space really, it’s just an alcove where the shelving units weren’t quite long enough. He can just fit his shoulders between the shelves and the back wall, but that’s fine by him, it means he doesn’t need to concentrate on staying upright, the furniture’s doing it for him.
He presses his hips forward as Derek moves from his neck to his throat, starts nipping upward, and realizes they’re both hard as rock. This could go a whole hell of a lot further than his impromptu game of footsie had intended. Though, he will admit, he had shucked off a shoe and pressed his foot to Derek’s groin. So maybe it was more than a little bit his own fault.
Derek nips at his lips and he stifles a moan, gives in and kisses him almost desperately, presses their hips together.
Derek bucks against him, drags his mouth away, growls a little.
“Shhh, jesus.” Stiles doesn’t stop rubbing against him, though.
“S’fine, no-one’s here.”
Stiles squeaks a little as Derek’s hands grip his hips tightly, as he presses even harder against him.
“No - no one’s here?” He can’t help the stutter, Derek’s starting to rock, their cocks sliding against each other through the layers of clothing. He really needs to get their pants out of the way.
“Upstairs,” Derek intones, mouth pressed against Stiles throat again, lipping at the enormous hickey as his hips move in aborted little thrusts, “Lunch break. Probably forgot we’re here.”
Stiles shudders, decides fuck it and grabs at Derek’s fly, “Awesome. Fuck. We can - we can totally-” He cuts off when Derek bites down, hard, breaking into a moan that has him shoving his wrist into his mouth.
His fingers have gone slack on Derek’s fly, but it doesn’t matter because Derek pushes his hand aside and does it himself. Stiles can barely move as Derek laves at the bite, but he hears the slight hiss of the fly being lowered, feels Derek’s cock suddenly pressing bare skinned against the front of his slacks. He makes a grab, wraps his fingers around it, jacks it a few times and Derek groans wetly against his brand new hickey.
“Want you. Stiles, fuck, in you, now.”
Stiles would protest, but apparently he doesn’t want to. Apparently that sounds like a fucking fantastic idea. Neither of them have removed any clothing, Derek’s dick standing straight out through his fly, but that apparently doesn’t bother him either - he’s learning all sorts of things about himself today.
He grabs Derek’s mouth with his own, kisses and kisses and kisses, deep and wet and dirty as Derek pushes one hand down the back of his slacks, presses two fingers into his crack through his boxers, pressing and sliding. Stiles pants as they break for air, “Please - please tell me you have-?”
Derek nods, digs into a pocket with his free hand, busy fingers never leaving Stiles ass. He pulls his wallet out, flicks it open and Stiles reaches in to grab a condom. He couldn’t be more pleased that the damn thing’s pre-lubed.
Derek drops the wallet and sucks two fingers into his own mouth, eyes meeting Stiles as Stiles tears the packet open with his teeth. “Fuck, Derek.” He tries not to moan as Derek keeps his other hand down the back of Stiles slacks, pressing, rubbing, sliding, fucking teasing.
Stiles swallows and rolls the condom down Derek’s dick. Derek’s eyes close as he does, but he keeps sucking on his fingers and Stiles knows exactly where they’re about to go, he’s way too damn eager for them.
“Fuck,” he says again and pulls away from Derek’s teasing fingers, twists and turns around, faces the wall. He looks over his shoulder at Derek, catches his eyes again as he slides his slacks, then his boxers down, just enough to give Derek access. Fuck, he is going to have so much 'carpet'-burn on his ass after this, he just knows it.
Derek presses in close again, chest to Stiles back, mouths the the back of Stiles neck. “Stiles...”
Stiles pushes his hips back, deliberately rubs his ass over Derek’s erection, eliciting a moan that is pressed into the nape of his neck. Derek’s free hand snakes up under his shirt, spreads over Stiles chest; teeth sink into the nape of his neck, almost gently and Derek spreads Stiles cheeks and pushes his wet fingers into him.
Stiles bites back a yelp, sticks his wrist in his mouth again, bites down on it as Derek fingers him quickly, thrusting into him as deep as he can, scissoring and spreading as far and as quickly as possible. Stiles whimpers around his wrist, pushes back into the thrusts, wants more, wants it now, doesn’t care. “Fuck fuuuuuck, Derek, come on, oh god.”
Derek grunts, pulls his fingers free and a moment later, Stiles can feel the blunt head of his cock pressed to his hole. “Oh god, come on, get in, get i-uhhnnn!”
Derek wastes no time, he pushes in with one huge, hard thrust, as far as he can.
Stiles only just manages to stifle his groan, and Derek’s hands grips his hip so tightly he knows he’s going to be sporting bruises for a week. He doesn’t get time to adjust. Derek flexes and then he’s moving.
“Fuuuuuccckkk,” Stiles groans around his wrist, as Derek thrusts hard, fast, so fast, so fucking fast. Derek’s teeth sink into the nape of his neck again and Stiles drops his head forward, against the smooth wall as Derek pummels into him. His knees quake, his hips jerk, Derek thrusts hard and as deep as he can and Stiles swears he can feel it all the way up to his throat.
His throat that is betraying him with moans and pants and cries breaking around his wrist, getting louder, more insistent the harder and longer Derek thrusts into him. He can’t stop himself, he fucking loves this, loves being filled and filled and filled, has to let Derek know, let him know what he does to him.
Derek grunts and the hand on Stiles chest slides away. A second later his wrist is tugged from his mouth, and his aborted question is muffled almost immediately as Derek’s huge square hand fits over his mouth, shutting him up completely.
And that - that - that’s apparently another kink he didn’t know about. His eyes drop closed as he grips at Dereks wrist, tight enough that he’d leave bruises if Derek were human. His other hand lifts and falls back, into Derek’s hair where he clutches and tugs, as many points of contact as they can get in the cramped space.
The hand on his hip moves, slides around his middle, tugs him closer, tighter, holding their bodies so close, so fucking close. Derek’s breathing begins to stutter, his thrusts longer and harder, hard enough to force Stiles own erection against the shocking cold of the wall with each forward movement.
“Fuck - Stiles.” Derek’s teeth leave his neck, replaced with harsh, panting, wet breaths and Stiles knows Derek is almost done for, can feel it in the way he moves his hips, presses his damp lips to Stiles skin. “Fuck - I c- I can’t.”
Stiles can’t tell him to just fucking go ahead, so he nods frantically, pushing his ass back onto Derek, matching the thrusts into him and Derek takes the hint. He thrusts harder and harder, even faster than before, until - Stiles groans as Derek pushes as deep and hard into him as he can, pressing Stiles into the wall with the force of it, as he stills and pants, swallowing a moan as he grips tightly to Stiles body, coming and coming and Stiles imagines he can feel the pulse of it against his rim.
Derek doesn’t wait, as soon as he’s finished, he pulls out, drops to his knees and pulls Stiles round. Stiles resorts to sticking his own wrist in his mouth again as Derek greedily sucks him in down to the root. He stifles a squeak.
Stiles free hand drops into Derek’s hair again, a loose hold, something to do as his brain fizzles, stops working. Derek works him hard, sucking and laving and twisting his hand around the base as he lips at the tip. Stiles chest heaves and as Derek presses two fingers back into him, crooks them just so, he whines, tugs at Derek’s hair suddenly, a warning.
Dereks sucks him all the way in again and Stiles tenses, stomach clenching, everything clenching, as his orgasm hits him, pulsing and pulsing down Derek’s throat.
He’s pretty sure he whites out for a moment, because the next thing he knows, Derek is tugging his slacks back into place - his ass is sore in so many interesting ways - and mouthing at his jawline. He turns his head, grabs Derek’s mouth with his own and kisses him sloppily, can still taste himself on Derek’s tongue. He wraps both arms around Derek’s neck as they kiss and it takes a long while for them to pull away for air.
“Fuck, we are totally doing that again. Like, everywhere. I’ll make a list - ‘places to fuck where we might get caught and Derek has to gag me’.”
Derek snorts at him, but doesn’t say no.