Derek's face is disapproval all over. "Are you going to work out dressed like this?"
Stiles looks at his jeans and t-shirt. "I guess? I could go home and change first if you want." Breaking into the gym was kind of a spur-of-the-moment thing, okay. Excuse Stiles for not having his gym clothes in his bag while attending a werewolf pre-full-moon meetup. "Hey, if I'm running away from assholes, I'll probably be wearing something like this anyway."
That just makes Derek's scowl deepen. "You don't want to limit yourself when you train."
Stiles crosses his arms across his chest. "You got a better idea?"
Wordlessly, Derek fishes something out of his pocket and dangles it in front of Stiles' face.
"You're kidding me," Stiles says as he accepts the jockstrap. He flushes and gulps, staring at Derek's extremely smug expression. "What kind of person just goes around with underwear in his pocket? If you wanted me almost-naked, you just had to ask."
Derek lifts one eyebrow, and Stiles figures out that huh. Maybe this is asking. It's kind of drafty in the gym, but hell, he'll probably warm up in no time.
Maybe not exactly soon enough, though. "What do you want," Stiles grunts as he stretches. Derek's eyes are glued to his chest. "It's cold, they stand up. Biology, bi-atch."
"They're still red from yesterday," Derek says, and shit, is that a hint of fang when he opens his mouth?
Stiles stumbles, covers for it by saying, "Well, yeah, that happens when you treat parts of my body like chew toys." If he's turning a little red – in the face, never mind other parts – because he's remembering what that felt like, so what.
Derek hauls Stiles up to his feet. "That's enough stretching," he says. Stiles is very much aware of the jockstrap fitting nowhere near as well as before, because shit, does Derek have to make that sound so filthy? "Let's get to work."
When Derek said he'd provide motivation, he wasn't kidding. Right now he's kneeling between Stiles' legs, eyes intent on Stiles where he's attempting sit-ups.
"This isn't just for strength," Derek says as Stiles hauls himself closer to Derek, stomach muscles trembling. "It's good for flexibility, too. I used to be able to suck my own dick when I was younger."
The shock of hearing that is enough to push Stiles so his elbows make contact with his knees. "Fuck," he moans, sinking back to the floor. "How can you just say that?"
"I can smell that your dick is hard," Derek says, like that isn't also evident to anyone with eyes. "Don't you want to get closer, put your mouth on it?" He slinks around to whisper in Stiles' ear. "Your mouth feels very good, just so you know."
Stiles pushes up one more time. Then lies limp on the floor. Enough.
Derek lifts up the cup of Stiles' jockstrap and does nothing except breathe against him.
Stiles whimpers. "I hate you." He pushes up for another crunch, eyes screwed shut because he just can't look at Derek right now.
"Lift your legs up," Derek says. Stiles obeys, flexing his hands against the pull-up bar. He's not feeling the burn yet, which would be more satisfying if Stiles didn't know he weighs about the same as a wet kitten. Derek proceeds to step between Stiles' raised knees and put his mouth on Stiles' balls.
Just--literally puts his mouth, without any of the fun activities Stiles normally associates with this phrase, such as sucking or licking or even nuzzling. Nothing but the simple touch of Derek's lips against Stiles' balls through the jockstrap.
"You are the worst human being ever," Stiles says in a conversational tone.
"Bring your legs up further," Derek says, breath ghosting against Stiles' inner thighs. "See what happens."
Stiles does, and oh shit Derek's mouth is right on Stiles' ass, hot tongue licking Stiles' cheek, moving closer and closer to the center--
Stiles' legs drop down in shock, and Derek moves away. Stiles takes a huge gulp of breath. "The worst," he says with conviction, before bringing his legs back up.
"I hope you're not. Expecting me," Stiles says, breathy and halting, "to develop – ah! – abs. 'Cause that's. Totally. Not happening Jesus fuck don't stop."
"Don't drop your legs and I won't," Derek says, like that's a perfectly reasonable demand. Stiles may or may not sob a bit.
After a few short eons, Derek steps back. "On the floor," he says. "Stretch."
Stiles' arms are just feeling the burn, but his abs are done for today. He curls into a ball, rolling back and forth.
"Not like that," Derek says. "On your back. Bend your knees. Now lift your ass, bend your back up – yeah, like that," as Stiles bends into a half-wheel. "Spread your legs more."
"Are you sure that's contributing to the stretch," Stiles says faintly. He can feel the heat of Derek's eyes on him, shudders as a stray draft tickles the hairs on his legs. Derek looks like he's measuring something, and Stiles has a notion that it's not just his measly endurance.
"Alright, stretch your arms and back on the bar," Derek says. Stiles hurries to obey.
Three repetitions of this leave Stiles exhausted, harder than hell, and so frustrated he's going to scream. As long as Stiles can keep his legs up, Derek will lick into him, slow and leisurely. He won't add fingers, no matter how much Stiles begs for them. Won't step up the rhythm. When Stiles is stretching, Derek won't touch him at all.
Both his arms and his stomach muscles are burning now, but it's nothing to the ache in Stiles' balls. "Derek," he says, a weak plea.
"Push ups, now," Derek says, and Stiles is growing convinced that he is actually Satan.
"No," Stiles groans, flopping like a fish. "Can't we call it a day? I need sustenance. I need a shower." He needs to come, but he's got a feeling saying that out loud won't help at all.
Derek comes to crouch next to Stiles. The hem of Derek's jacket is right next to Stiles' mouth; Stiles wonders if it's normal to want to bite into it, suck at the leather. "You need to be prepared," Derek says with soft urgency. He pets Stiles' hair, slowly, so not fair. "You need to be strong and fast. You're smart, but smart isn't always enough."
Stiles turns his face. Derek lets Stiles nuzzle his palm for a minute before he grabs Stiles by the arm and rolls him over. "Push ups," Derek says. "Now. For every ten, you get one."
"Every five," Stiles counters on instinct. "Wait. One what?"
Derek pretty much plasters himself against Stiles' back, holding himself up on stretched arms with no discernible effort. "One thrust," Derek says into Stiles ear. "Ten to one gets you your cock in my mouth. Five to one gets your pretty little hole fucked."
"Who the hell decided on these exchange rates," Stiles chokes up, but he's pushing away from the floor and into Derek's warmth before he even thinks about it.
Normally Stiles can do about forty push-ups, fifty on a good day. He breaks past that without even noticing, pulled down by gravity and up again by Derek's voice in his ear whispering obscene promises.
But even with that, he's got limits. Still, he figures he must've done an okay job; when he finally crashes, Derek doesn't attempt to coax him into more.
Instead, Derek twists Stiles' hand behind his back, and gently pulls his elbow until Stiles groans at the stretch. He repeats this a couple times before laying Stiles' arm by his side and starting again with the other arm.
When he's done, Stiles is one limp noodle... except for his dick. His entire physical ability to stand up seems to have drained to his crotch. This means he can't exactly fight when Derek pulls him up yet again, but he can sure as hell complain about it. “Derek. Please. No more. I am dead, do you realize this? I am Alpha prey. Put an apple in my mouth and serve me up for dinner, because I am done.”
"Got better things to put in your mouth,” Derek says, and Stiles can't help but perk up and pay attention to that, just as Derek lays him face down on the pommel horse. “So. Five or ten?”
"Uh.” The air goes out of Stiles. He squirms until he's got Derek in his line of sight. “This position is totally not conductive to unbiased decisions, just saying.”
It’s really not, because Stiles has his ass on display, and he’s uncomfortably aware of how wet he still is from Derek's mouth, how open, how Derek could probably just slide a finger right into him, easy and comfortable.
Derek smirks, unrepentant.
"And you skewed the exchange rates, too.” Stiles lets his head fall forward, the fake leather of the pommel horse tacky against his forehead. “Alright, go ahead and fuck me, you fucker.”
There's the (by now familiar) sound of a lube packet being torn open, but even though Stiles strains, he can't hear Derek unzipping his pants. Stiles groans and wiggles his butt in hopefully an enticing manner. “C'mon, Derek, stick it in me. You promised.”
"I said you'd get something thrust up your ass,” Derek says. There's a weird squeaky noise, like rubber rolled onto something that is definitely not human flesh. “Didn't say what.”
At first it's just Derek's fingers, anyway, familiar and teasing right at the edge of Stiles' prostate. Stiles groans. “This better not come off the final count, Derek, I earned this fucking fair and square.”
"Fingers fall within the definition of fucked,” Derek says, but he's pretty liberal with the fingering. Stiles is pretty sure he'd already be past his quota if they were keeping count.
Then there's something at Stiles' entrance, larger than fingers but not the comforting blunt warmth of Derek's cock. It's smaller,but harder, barely any give at all. Stiles sneaks a glance back, then blinks. “Are you actually fucking me with a lacrosse stick?”
The worst thing is, even as Stiles says it he feels his cock plumping further, dripping against the pommel horse.
"Knew you'd like it,” Derek says, warm and content like he's just glad he guessed right about Stiles' tastes. Stiles stifles a moan and pushes back. “Next time I'll get you a plug, you can keep it in you as you work out. Train you to keep on in spite of distractions.”
"I could swear you said something about limitations earlier,” Stiles mumbles. He might be drooling, he can't quite focus on anything except the stretch in his ass. After the initial intrusion it doesn't keep burning like Derek's cock does, but the pressure against Stiles' prostate is absolutely unyielding.
"Fourteen,” Derek says, like that's a reasonable answer, and he pulls the stick out of Stiles.
Stiles seizes up, almost falling off the pommel horse. “Wait, why-- bring that back here!”
"Fourteen thrusts,” Derek says, implacable. “That's what you earned, that's what you get.”
Stiles doesn't even have the energy to protest. He just mutely clutches the pommel horse's sides, ass contracting on nothing but empty air. “Derek,” he says after a moment of just looking pitiful doesn't have the desired effect.
No response, so Stiles adds, “You could at least let me fuck myself with the stick, if you're not gonna.”
That gets him a sharp exhale. Stiles smirks to himself, grinning wider at the sound of a zipper finally sliding undone. “Come here,” Derek says, coarse and rough. Stiles climbs off the pommel horse with trembling legs, walks to where Derek is lying down on his back.
Except for his angry-red dick poking out of unzipped pants, Derek is almost entirely clothed. Stiles straddles his hips, flushing at the sensation of denim against his naked thighs. Derek reaches up a lazy hand to tweak Stiles' nipple, making him gasp.
“Turn around,” Derek says, putting his hands around Stiles' waist and pushing until Stiles is kneeling over Derek's dick and looking at Derek's inexplicably bare feet. The sight of Derek's wiggling toes is an odd sort of comfort.
Then Derek seats Stiles down, pushes his cock up into Stiles with a single effortless thrust of hips. Stiles shouts, head thrown back, helpless. Derek's hands keep Stiles' palms pinned to the floor.
"Wanna come?” Derek's voice is low and so rusty Stiles will probably need a tetanus shot later. “Work for it.”
Stiles is all out of awful names to call Derek, so he just sobs, working himself up and down on Derek's cock. There's an angle that consistently makes Derek's cock rub against Stiles' prostate, but once Stiles gets the rhythm he likes he can't keep the position. He has to work his legs to get a thrust going, keep his abs tightened not to fall over, and his own dick is so hard Stiles bets he'd come from someone just breathing over it.
"Derek,” he cries out, “Derek, please,” as his legs wobble and give out, until Derek finally, finally flips Stiles to his belly, sliding back in with a grunt and riding him mercilessly.
This is better, because Derek has that angle down flat, so good at this it's almost scary. He props Stiles' hips up and drives into him over and over, nailing his prostate with pinpoint accuracy and all Stiles has to do is ride that wave until it crests and splashes.
Messily. All over the gym floor. But Stiles just flops down in the mess he made, sighing contentedly, and figures he'll clean it up later.
Derek's still thrusting, but he's slowed down some. His hands clench spasmodically around Stiles' shoulders, his mouth sliding restless between Stiles' shoulder blades. Stiles spreads his legs, arches his back and puts his hands over Derek's, entwining their fingers until Derek pushes into him and stays, shivering.
Stiles twists back and Derek meets him halfway, till they're kissing with Stiles awkwardly bent in a way that will make his back start aching in roughly half a minute. He stays in place anyway, figuring that who cares about one more hurting body part. Derek pulls out and away, saying, “You'll wrench something like that.”
Stiles just hums something and melts into a happy puddle on the floor. He's vaguely aware of Derek moving things around him, but he only really gets it when cold water drips on his back.
"Ugh,” he complains, turning over. Derek cleans up Stiles' stomach, quick and thorough, soon helping Stiles to his feet. “You better carry me to the jeep, I don't think my legs work anymore.”
Derek rolls his eyes, but he lets Stiles lean against him on the way back to the car, and when they're back at Stiles' currently-empty house, Derek draws him a warm bath and rubs him clean with the same laser focus he gives sex and territory protection.