Work Text
Stiles knows this is risky, he knows, okay? But he can't seem to stop himself. He saw the porn video of the modified exercise bike and his mind started whirring. The thing is, though, he didn't have an exercise bike. But he had a normal bike. And a lot of unsupervised time. Modifying his clothes takes a lot of weird testing, lots of marker stains and adjustments, but eventually he thinks he's got what he needs. He goes with an older, baggier pair of jeans - he figures those might pool around the holes he'd cut, hide everything from view. He forgoes underwear because really, what's the point?It's a little more work to find something to hold his favorite dildo in place that won't be permanent. He needs it to stick but he doesn't want to explain it later. He digs the hot glue gun out from an old craft box, makes sure it's warm enough to melt but not so hot it'll scorch the silicone or the rubber of the seat. He's meticulous with the glue and the placement, holding the dildo steady as it sets, cock already starting to fatten up in his jeans.When everything is ready, Stiles moves over to the towel he'd laid out on the garage floor, carefully laying down on his back and popping the cap off his lube. He leaves his jeans on, sliding his fingers through the makeshift hole and over his pucker, only teasing a little before pushing the first one in. He doesn't waste time, his heart thudding hard in his chest in anticipation, instead methodically works himself open until he his hips are hitching down to meet the thrusts of his four fingers. He doesn't actually need to be stretched that wide, he doesn't think, but since he's going to be moving a lot, he figured it was better safe than sorry. It's an effort to drag his fingers free, to not give in and ride them to orgasm, but Stiles manages, and then gets up off the floor. His legs are shaky already from exertion, but he's not done yet. He snatches up the garage door opener with his clean hand and drops it in his pocket before wrapping his slick hand around the dildo and stroking it. He can feel the catch and drag of the silicone against his calluses, so he drizzles more lube over the tip, slicks it down the length, making sure it's coated all the way to the base, and then he straddles the bike. It's more effort to lift himself up to the right angle, takes some careful bracing, but eventually he can feel the fake head pushing against his loosened hole and he starts to slide down the shaft, groaning softly as he spreads open around it. The dildo is unyielding in the best way, stuffing him full, not allowing him to shift back and forth on the seat. He can't stop the moan when he finally hits the base, clenches around it just to feel the girth. He takes a second to wipe his slicked up hand off on the inside of his shirt before wrapping it firmly around the handlebar. Stiles jabs at his pocket, engaging the button for the garage door, with his other hand before reaching back to make sure his jeans are covering the dildo. It all seems good and he wraps that hand over the bike's other handlebar, lifting one leg to a bike pedal and feeling the way it forces him to shift on the dildo, stifling a moan as it presses against his walls. As soon as the door is out of the way, Stiles lifts his other foot and begins to pedal, every movement shifting and jostling him over the dildo. He has to bite the inside of his cheek to hold back the noises trying to escape, especially when part of the toy hits against his prostate on every other pedal. His cock is fat against his belly where he'd had the foresight to tuck the head behind the waistband, the hair on his happy trail coarse against his skin. Even with that to keep him back from the edge, he can feel himself leaking, is glad he picked an oversized shirt too. His neighborhood is surprisingly empty as he rides, and he can't help but take a little advantage, lifting himself up slightly as he pedals before dropping back down, mimicking what he'd seen on the modified exercise bike, fucking himself as he rides. It's thrilling, knowing anyone could catch him, and it makes his cock leak harder.By the time he turns out of the neighborhood, he's not sure how much more he can take, if he's honest with himself. His hole is spasming around the dildo, his cock is leaking so much he's pretty sure it would look like he'd pissed himself if the crotch of his jeans wasn't hidden by his shirt, and his body is trembling slightly from the exertion of riding and fucking himself up and down on the toy. He thinks about turning back around, especially when he can see people ahead and he can't hold in the whimper as his cock twitches, the thrill of potentially getting caught ratcheting up even higher. He blames the adrenaline spike on his failure to pay attention to the stop sign, because he rides right through it as he spins back towards the neighborhood, without noticing the sheriff's department cruiser parked just behind it. The flash of lights and unmistakable quick whoop of the siren has his heart thundering for an all new reason as he finishes his turn back onto the sleepy street he'd just exited. He rides against the curb, planting one foot on it to hold himself steady, bites back another moan as it forces the dildo against his prostate. He can hear the door of the cruiser open and close and is afraid to look back, afraid that it's his father coming up behind him. “Stiles.” And fuck, it's not his father, but he's not sure this is much better. He tries to put on his best 'I didn't do it’ face as he turns his head, biting his lip and clenching around the toy as Derek saunters into view. Stiles has never regretted anything as much as he regrets encouraging the alpha to join Beacon Hill's finest, not least of all because Derek in a deputy uniform is nothing short of pornographic - Stiles never wanted to associate anything to do with his dad's job to sex, but there it is.“Derek….heyyyy. Uh, what's up?” Derek's brows go up behind his sunglasses, nostrils subtly flaring, before a smirk drags its way onto his face.“I think you might have a better answer to that question. Why don't you go ahead and step off the bike Stiles.” It doesn't come out as a question because it isn't one, Stiles knows. Except he can't.“I, uh, can't really do that. Right now.”“Care to explain why not?”“Not really.” Stiles cringes as the words leave his mouth, knowing Derek's not going to let it go.“No?”“Uh, no.”“That's not really going to work for me. Me, deputy,” Derek points to himself before turning his finger towards Stiles, “you, person who just broke a stop sign law. As an officer of the law, I should be citing you, but first I'd like to make sure you're not intoxicated, seeing as how you blatantly broke the law right in front of a deputy.” Derek's smirk grows and Stiles can feel his face turning red. Surprisingly (or maybe not) his cock hasn't softened at all, in fact...it feels like it's getting wetter. He tries to muster some indignation, sputters back at Derek.“I'm not intoxicated, it was a mistake. One we both know I won't make again. Can't you just let me go?” The last words come out in a whine and Stiles would be embarrassed but he has no more room for that, not with the way he's sitting there, a dildo snugged up in his ass, cock pushing against his belly, while Derek harasses him and yet, his body can't get the memo that he shouldn't be more aroused by it all. Stiles is too lost in his thoughts and misses it when Derek steps closer, until he's right up against Stiles’ side.“Stiles.” Derek's voice curls darkly against his ear, startling him. If anyone saw them right now, they'd get the wrong idea with how close Derek is. “What have you done?” The words are quiet, barely there, but before he can try to deny whatever it is that Derek's thinking, Stiles feels the brush of fingertips against the cheek of his ass, over his jeans. He doesn't even try to hide the shudder as the fingers dance over the material, creeping towards the hole he'd cut. Stiles can't stop the way he rocks up and down, just a bit, forcing his body to shift around the unyielding dildo. Derek doesn't miss it either, fingers skating faster over the fabric until they find the ragged edge, push past it to bare skin.Stiles’ eyes are locked on the crotch of Derek's uniform pants, sees when his cock twitches inside them. It gives him the courage to meet Derek's gaze, even as he can feel Derek's fingertips skimming over his hole, feeling the way he's slick and stretched around the toy. He's about to open his mouth, say….he's not sure what actually, but Derek's suddenly pulling back, stepping away. The sounds of the neighborhood spark to life around him again, and Stiles realizes someone was coming outside a few doors down, getting into their car after Derek tosses them a friendly smile and wave, his posture forcibly relaxed. He keeps his distance from Stiles as the woman starts her car, backs out of her driveway and then rumbles down the road, waving as she passes. As soon as she's turned out of the neighborhood he's crowding back up against Stiles, hand pushing between his ass and the bike seat, fingers pressing against his rim. “I think you need an escort home, don't you?” He doesn't wait for Stiles to answer, grinding against Stiles’ hip as he keeps talking, fingers not stopping their movement either. “I think we need to talk about today's little adventure ride, your...interest in public service. And speaking of rides,” Derek's voice goes impossibly lower, “I think you should ride home. Hard. I'll be right behind you. Watching to make sure you get home safe.” Derek's fingers slip out from beneath his ass as he backs off again, this time slower. He keeps eye contact as he slips them in his mouth, licking the taste off of them as he moves backwards towards his car. Stiles’ cock throbs harder, but he doesn't move to leave until Derek is settled behind the cruiser's wheel. Stiles hopes to god Derek doesn't have the dash cam on when he pushes away from the curb and begins to pedal, body trembling harder than before as he rises and falls in time with his pedaling. He's lifting further, his balls drawing up tight as he rises up, knowing that if anyone looks outside, there's no mistaking any of this - he's nearly coming completely off the dildo each time, wanting to give Derek a real show. He's going hard enough that he can't fight the whimpers and moans, especially not when he thinks about how he must look, hole spread wide, puffy and red from all of the friction, sliding up and down the silicone dildo. His cock is basically pouring out pre at this point, and he barely makes the turn up his driveway and into his garage before he's dropping a foot, twisting sideways with the angle of the bike as his balls tighten and he doubles over, come painting his belly and the inside of his shirt.Over his own whimpers, Stiles can hear the crunch of the cruiser's tires before it shuts off. Derek doesn't waste any time getting out, the door slamming behind him as he strides up the driveway, department issue boots slapping loudly against it. Stiles is still twitching through the aftershocks, ass clamping down on the toy where it's still buried in him. Derek steps up behind him, and Stiles frantically paws at his pocket, hearing the grinding of the gears as the garage door begins to lower. It can't be more than halfway down before Derek is moving even closer, tugging Stiles up and off the bike. When Stiles’ feet are firmly planted, he starts to turn, but firm hands on his hips keep him in place. The air shifts as Derek drops down to his knees behind him.“Let me…” his voice is rough, and Stiles is glad to hear the facade drop.“Yeah.” He isn't actually sure what Derek's asking for, but he doesn't care. “Bend over.” Stiles does, hands gripping a box to help him balance. He's expecting it when Derek thumbs his hole, but not when Derek grips the frayed material and yanks it apart further. His spent cock twitches, tries valiantly to get hard again. Derek's palms cover his cheeks, pull them further apart so he can stare at Stiles’ hole, and it makes him blush, but he doesn't hate it. He can feel the way it's not closing up tight, not after how long he was stretched out around the toy, and wonders if Derek likes what he sees. He tightens involuntarily, hole clenching and releasing, and he can hear the ragged breath Derek lets out, feel the wash of air over his pucker. “Fuck!” Stiles thanks everything that his father isn't home when Derek leans forward and drags his tongue from his taint to the top of his crack. He doesn't even have time to catch his breath before Derek's lapping hard at him, tongue sliding between his cheeks, dipping into his rim as it glides over him. Derek's tongue is relentless, and Stiles’ cock wakes up under the attention. He scrabbles at the front of his pants, untrapping himself as he undoes the button and zipper, but when he reaches to wrap a hand around himself, Derek slaps his hand away, gripping Stiles’ erection himself, even as his face pushes against Stiles’ ass harder, tongue fucking into his hole.“Mrfph.” Whatever Derek is trying to say is lost because he won't move his face back far enough to speak.“What?” Stiles doesn't want Derek to stop, but he can't understand him as more garbled words are spoken against his hole. He does understand when Derek tugs on his hips, pulling him backwards as he shifts, laying back on the floor. Stiles is careful as he follows, does his best not to fall - not that Derek's strong grip would let that happen - until he's straddling Derek's head. He doesn't resist when Derek pulls him down harder until he's practically sitting on Derek's face, tongue buried back in his ass. With Derek's encouragement, Stiles grinds down, making them both moan, and is rewarded with Derek's hand encircling his cock, grip tight enough to give him something to fuck up into as he lifts himself with trembling thighs before grinding back down.They get into a rhythm quickly, Derek's tongue thrusting up to meet Stiles’ ass every time he shifts back down. Stiles braces himself on Derek's thighs, his own getting weaker by the second, his grip pulling Derek's khaki's tight over his erection. Stiles shifts his hands so his thumbs can stroke over the bulge as he rocks on Derek's face, watching the small wet patch darken and spread. It doesn't take as long as he thought it would before he's shuddering as he rocks, balls tightening again before Derek grips his cock tight, stroking in counterpoint to Stiles’ movements, and he's shouting out his release.Stiles damn near faceplants in Derek's crotch, Derek's tongue still delving into his oversensitive hole, and he doesn't fight the urge to mouth at the bulge, sucking hard when he feels the ridges of the flared head through the material. Derek bucks up as Stiles sucks before soaking the front of his uniform pants with his own come, Stiles grinning against him as he licks at the wet fabric, the tang of spunk strong. Derek's tongue finally stops as he's coming, and Stiles sighs in relief before outright laughing as he feels Derek's lips press against his pucker in a gentle kiss.“Shut up. Killing the afterglow.” Derek swats softly at Stiles’ ass and Stiles squirms forward a little more, still licking softly at the wet patch. “You're the one who just, literally, kissed my ass.” Derek swats him softly again but Stiles can hear the soft laugh he lets out as he does it. They lay in silence for a few minutes more as they come down from the endorphin rush, before Stiles wiggles his way off of Derek, sliding onto the floor next to him and hissing when his bare ass meets cold concrete.“So, I have tomorrow off.”“Hmm?” Stiles sits up a little so he can meet Derek's gaze.“Thought you might want to go for a bike ride together in the preserve?” Derek's eyes flick towards the toppled over bike, dildo still covered in lube and glistening. Stiles’ gaze darts between Derek's face and the bike, seeing the unmasked lust.“Hell yeah.”