Derek certainly hadn't come into the locker room with the intention of spying on Stiles - he was looking for Scott. He had heard them talk about how they usually volunteer to clear up the equipment after practice so they could be the last ones in the locker room and talk about monster-related things without being found out.
Of course, Derek's intentions matter when he soon realised that Scott wasn't in the locker room, and it was just him and Stiles. The showers were on, and Derek saw the steam coming from round the corner leading to the showers. God, this was just like a cliché porno, and Derek was playing his part wonderfully.
The room was devoid of equipment, save for Stiles' gym bag sitting on one of the benches, a jockstrap tossed haphazardly over it. Derek looked down at the offending garment - it was sweaty. Stiles probably wore it in practice, along with the pair of socks sitting on the ground. He held the jockstrap by the red strap, brows furrowed as the scent of Stiles sweat and musk filled his nose.
God, he was such a pervert. His dick was chubbing up in his boxers, a noticeable bulge forming against his jeans. If he had any semblance of self-control, he'd put the underwear down and leave Stiles to his shower, going to Scott's house to tell him about how he dealt with a Werebear that was moving through Beacon Hills.
He didn't do that. Instead he lifted the dirty jockstrap up to his face and took a whiff, fondling his bulge as the scent of Stiles' sweaty balls filled his nose. He almost lost control completely, letting his claws pop out slightly. He had to restrain himself from going into the shower and knotting Stiles' tight ass then and there, filling him full of cum and knotting him deep.
Imagining the scene wasn't helping, he continued to inhale Stiles' musk while thrusting his hips forward slightly, grinding his cock against the fabric of his underwear. He couldn't help himself any more, slowly walking towards the showers to get a peek at the insufferably sexy teen himself. He truly wishes that he hadn't.
As he peeked around the corner, he saw Stiles standing there, bent over picking up a bottle of shower gel off of the floor. His tight, pink pucker on display for Derek to see. He should have known that Stiles would shave his ass, making it even more of a struggle for Derek to resist walking forward, bending Stiles over, and rimming out his smooth ass until its red and sensitive. He wanted to make Stiles cry with how much he wanted to cum, he wanted to dominate him completely.
As Derek became lost in his fantasies, he grew careless. His hand was down the front of his jeans, fisting his cock as he watched the unaware teen. Evidently, he wasn't being as stealthy as he thought. He huffed out a heavy breath, making Stiles stand up straight, before grabbing a small vial of liquid from the ground and tossing it at Derek's direction.
The glass shattered on the floor, a cloud of purple vapour rising up to Derek's face. A shiver ran down Derek's spine as he realised that he'd been caught, raising his hand to his mouth to try and avoid inhaling any of the cloud, but it was too late. He feels lightheaded and collapses onto the locker room floor. The last thing he sees is Stiles staring at his, surprised and confused.
Damn, this is going to be tough to explain.
He has no idea how long he was out for. When he woke up, it was to Stiles standing over him, wearing just his jockstrap and socks, a smug smirk plastered on his face. His hair was still damp, so Derek assumed it wasn't long.
Derek didn't give the kid enough credit. He always thought that he was hopeless, and would never survive in a world of werewolves, hunters, and whatever else found its way through Beacon Hills. Obviously Stiles was smarter than he seems, to have access to Wolfsbane. At least it wasn't a lethal dose, maybe not even a lethal strain.
He was still groggy from breathing in the sour-smelling cloud. Groggy enough that it took him a while to realise that he was in his underwear, his hands bound above him. He pulled down, trying to break the ropes, but he couldn't, still too weak from the wolfsbane.
"Stiles.... what the fuck do you think you're doing?" Derek says, trying his best to intimidate the human. Clearly he's not doing a very good job. Even with everything but his junk and feet exposed, Stiles stands like he has the upper hand - and he does. Derek wishes he didn't look so fuckable, the last thing he wanted to do was pop a boner right now, but he supposes it's too late for that. Stiles already saw Derek with a raging erection, his hand down his pants staring right at him.
"Really, that's the line you want to take, buddy?" Stiles says, still looking smarmy. "I mean that tent in your pants was a pretty clear indicator of your intentions."
"What... no... I wouldn't-" Derek stammers. This is bad. He is so fucked. Scott is going to tear his throat out - with his teeth.
"Oh, hush, I get it." Stiles laughed, "You're too broody to go out and actually fuck someone so the slightest glance at a naked body gets you rock hard." Ouch. Derek recoils a little from the jab, he wishes it wasn't true. It's been months since he's got his dick wet, too occupied with Beacon Hills to even think about it.
Stiles straddes the bench, giving Derek a clear view of his bulge. The werewolf could catch a glimpse of Stiles balls, poking out at the edge of the small fabric. Shit. He's staring, and Stiles knows.
"Like 'em?" He chuckles, a hand settled on Derek's naked thigh. "I prefer them to boxers or briefs, more free, y'know?"
Derek tries not to focus on how in control Stiles sounds. For the sake of his pride. "I guess I don't need an answer considering you had your face buried in them." Derek closed his eyes, not wanting to look at Stiles face - judging and disgusted.
"You don't have to be ashamed of it..." He says, his hand edging ever so closely towards the growing bulge forming in the fabric of his boxers. "Everyone's got their kinks, y'know. For example, mine is a strong werewolf, tied down and unable to resist as I swallow his cum." Stiles chuckles darkly.
Derek is so fucked. Inescapably, irrevocably fucked. He wishes he didn't find that so hot, he just tries to muster a disapproving face, but his cock betrays him - straight up like a flagpole. There's even a tiny wet patch forming at the tip.
"Why don't I help you with that?" Stiles says, pulling the elastic of Derek's boxers down until his hard dick slaps against his abs, making the werewolf grimace with discomfort for a second. Stiles leans downwards towards Derek's cock. Most of the head was covered with his foreskin, just a small patch of pink skin exposed, already slick with pre-cum.
"Stiles, wait-!" Derek shouts, but the words slip away as a low moan escaped his mouth. Stiles slips his tongue underneath the older man's foreskin to lap at his sensitive cockhead. The confident bastard has both hands wrapped around Derek's huge cock, his tongue swirling around the head, collecting the pre-cum that the werewolf had pumped out earlier during his spy session.
Stiles lies on his stomach, leaning on the bench. Derek looks down at his ass, hairless and pale, cheeks slightly spread open from the position. Derek growled as Stiles finally takes his entire head into his mouth, moving downwards slightly, his tongue licking his shaft. He wanted to see his hole again, to watch at the teen's thighs quivered as his tongue fucked into his pretty pucker.
Evidently, Stiles' hole wasn't the only point of interest. Stiles had moved from fondling Derek's fuzzy balls, moving downwards and rubbing his hand against the man's hard taint. He began to move further south, rubbing a finger against the werewolf's twitching pucker. Derek imagined himself whining as Stiles stretched him out on his long fingers, pounding against his prostate while deepthroating his cock. The image itself was enough to make Derek pump out a small jet of pre-cum into Stiles mouth, his balls pulling up tight against his taint.
Thankfully, Stiles chuckled and withdrew his hand, going back to playing with his cock. His lips were red and wet with spit, and he was panting as he moved back down Derek's cock. This was terrifying - Derek was going to cum. Stiles hadn't even been sucking his cock for more than a minute. He clenched his teeth and growled low, flexing his toes against the locker room tiles as he tried desperately to hold back his orgasm.
Stiles didn't slow down like Derek hoped. Instead, he seemed to pick up speed sensing that Derek was about to blow his wad. He throated deeper, his nose buried in the small bush of hair at Derek's crotch, while both of his hands gently massaged Derek's full, hairy balls. Derek's eyes almost crossed as he teetered on the edge of orgasm, desperately making threats at Stiles to get him to stop.
Stiles didn't listen, instead the worst thing that Derek could imagine happened. He removed his hands from Derek's balls and reached back, pulling his cheeks open and revealing his tight, pink hole - which was now stretched around a dark plug. All Derek could think as he looked into the mirror behind Stiles was about was how he wanted that to be his cock inside Stiles.
And he came. Holy fuck, did he come. He let out a hoarse roar as his balls throbbed and he began pumping jets of cum into Stiles' throat. Stiles swallowed jet after jet of thick, werewolf cum as Derek's cock gradually got more sensitive and his powerful roar turned into pathetic whines. Stiles drew up off the cock until just the sensitive cockhead was in his mouth, suckling gently and drawing the last few trickles of wolf jizz out as Derek spasmes and shuddered.
They sat there for around half a minute, panting as Stiles smiled smugly at his captive, panting just as hard as Derek. His cock was rock-hard in his jockstrap and Derek almost wanting to lift Stiles up to his face, letting him hump into his mouth as he fucked him with his fingers.
But he was too ashamed to admit this, red-faced and breathing heavily as he comes to the realisation that he was bested and dominated by a fucking twink who's too smart for his own good.
"Okay... you've had your fun..." Derek pants, "Let me go."
Stiles laughs, a hand resting on Derek's pec, a thumb toying at his nipple, making him twitch in pleasure. "Buddy, the fun is hardly over yet." He reaches down and pulls the plug from his ass, Derek's cock takes attention immediately. Stupid Sexy Stiles.
"In fact, I think the fun's just starting." Stiles reattaches his lips to the head of Derek's cock. He's so fucked. He doesn't know what to focus on, Stiles mouth on his cock as he fingers himself in preparation for Derek's cock, or trying to ignore the fact that his strength has returned, and he could break out of the restraints any time he wants.
Derek is just so very fucked.