A/N: Here it is. Thanks for all the positive feedback on my first Sterek fic, by the way. I hope this last chapter will suit your fancy.
Stiles swallowed thickly as his plaid shirt sailed through the air and landed on his bed with the rest of his clothes. He was still wearing a dark blue t-shirt and ratty jeans, but they were to be gone soon too, because Derek was there undressing him, both literally and with his eyes.
Derek wasn't breathing, Stiles could tell, and therefore he was trying to get Stiles' clothes off as quickly as possible before he suffocated. But Stiles was clumsy and uncoordinated, and when Derek tried to yank his shirt over his head in one swift movement, it got tangled around Stiles' arms, making Derek growl when he had to pause and carefully slide the boy's arms back through and then take the shirt off with less fervor.
But once the shirt was off it went into the pile. When Stiles snapped his attention back to Derek, he saw the dude eying him up, raking his eyes over Stiles' pale, exposed chest and licking his lips. Stiles crossed his arms over himself diffidently. Derek looked like he was going to grab Stiles' arms, push them away, but he stopped himself. He stepped closer instead, placing his feet on the outside of Stiles', boxing him in against the door and being so close that it was like he was touching Stiles without actually touching him.
Derek's hands went for the fly of Stile's jeans. He unzipped them slowly, trying to catch Stiles' eyes the whole time, and Stiles couldn't help but to wonder vaguely why he wasn't undressing himself here, why he was letting Derek do it instead. Maybe because Derek was the Alpha, and Stiles was the human who could have his throat ripped out at any second. Maybe because Stiles was just too tired to think. These were great excuses, and he was going to stick by them like a farmer did his trampy daughter.
His jeans fell down off his hips, guided by Derek's calloused fingers. Stiles wanted to push the man's hands away, tell him to get his paws off the merchandise, but instead he wordlessly stepped out of his jeans. Derek bent down to pick up the jeans, and suddenly Stiles' head was reeling, because the werewolf had no business having his face that close to Stiles' crotch.
On his way to the bed, Derek grabbed the bag that Stiles had dropped when he walked in, which contained all the other clothes Stiles had been wearing over at Scott's house. He added them to the bed, and then climbed on.
"So, what, you're just going to sit on my clothes for a few hours? While I stand here in my Batman briefs?"
Derek just grunted at him, in a way that's answering him but not really giving him an answer.
"Why don't you just roll around a bit? Speed the process up. Dogs like rolling in things, right? I see the neighbor dog rolling in shit all the time."
The broody werewolf glared at him and growled, low and rumbling in his chest. That wasn't really an answer either.
"Is there something in that pile that's Derek'd up enough that I can put it on? It's a bit nipple-y in here."
"Why don't you just come sit next to me? I'll warm you up."
Stiles blinked, surprised, and then couldn't help the burning in his face. Derek had just made a lame attempt to flirt with him. Except it wasn't that lame, because it still made Stiles' face feel warm and his hands clammy.
Even though he knew the correct response was to make a snarky comment and then grab his sleeping bag and sleep on the floor, Stiles felt himself gravitate towards the bed, his arms held gawkily in front of him. Then he got to the bed and just kind of stood there uneasily, because how does one just sit in their underwear?
Derek solved that question for him by reaching out and putting his hands on Stiles' waist, and guiding the more human of the two forward so he was forced to climb on the bed, his thighs on either side of Derek's legs, touching. Stiles was taller than Derek now, so the man had to crane his neck upward to trace a line of hot, hungry kisses along the boy's jaw. Realizing his throat was quite vulnerable, Stiles pushed his neck down so his chin rested against his chest, but Derek just grabbed his face his pushed it up again, and started sucking at the pulse in Stiles' neck.
It was clear that they were both incredibly aroused at that point, if the bulge straining in Derek's tight jeans and the tent in Stiles' underwear, causing the Bat symbol to poke outwards, were any indication. Derek paused to undo his own fly and shove his jeans down his hips roughly, and then he ground his pelvis up into Stiles, causing a due amount of friction that made Stiles moan, long and tantalizingly. As Derek continued his upward thrusts, Stiles bit his knuckles, trying to stifle the sounds escaping his throat.
Stiles felt Derek's hands cupping his ass, digging his blunt nails into the plump flesh, trying desperately to pull Stiles down closer. His legs went up around Stiles' waist (damn was he flexible), trapping Stiles against him while he humped the fuck out of him, rutting and grinding and throwing his head back and letting his mouth gape deliciously. He bared his neck to Stiles, and that simple action sent tingles skittering down Stiles' body from head to toe. He realized now how much the Alpha wanted him, needed him.
They were both so close already. Stiles let his hand snake down between them and slipped his cock out of his underwear. Then he stuck his hand down Derek's boxer-briefs and grabbed his hard-on firmly, causing Derek to groan. He held both of their dicks in one hand—which was difficult, because his hands weren't terribly big—and started thrusting quickly, letting their erections slide together with the help of pre-cum.
But Stiles wasn't the most coordinated: his pace was erratic and he couldn't keep them both in his hand. Derek growled, swatted Stiles' hand away in frustration, and gathered them both in his own larger hand. The werewolf managed to match Stiles' pace perfectly, and after a few hard, fast thrusts, Stiles came, getting cum all over his own abdomen. At the sight of Stiles' eyes rolling back in his head in sheer bliss, his back arching forward, his legs clamping around Derek's thighs, a few last wayward thrusts racking his body, Derek came too, all over Stiles' chest.
Derek let go of Stiles' waist with his legs and pushed him off before the boy could collapse on top of him, not wanting to get his own clothes all spunky. Stiles frowned at the realization that he had been almost completely naked but Derek had kept all his clothes on. The werewolf grabbed one of the shirts from underneath Stiles and used it to clean Stiles off, then worked carefully to get Stiles' sensitive, soft cock back in his underwear. Derek pulled his own pants up while grinning down at the Bat symbol.
"I don't smell Scott at all anymore," Derek said smugly as he lied down next to the drowsy Stiles.
"Are you sure?" Stiles asked, lolling his head to look Derek in the eyes. "I wouldn't mind a repeat performance. We could role play too. Do you have a Catwoman suit?"
"I don't either. I have a Superman costume. How about you be Superman and I be Batman? But you aren't impenetrable, you just heal. And you're not really fit to be Clark Kent, he's got that whole nice guy thing going for him, and he's kind of geeky. Oh, how about Wolverine?! You would make a great Wolverine."
"Okay." Derek pressed a kiss into his forehead. "Go to sleep."
Stiles didn't need telling twice. He nuzzled his face into Derek's chest, while wrapping himself around the werewolf to absorb some of his constant heat. Derek pulled some of the clothes on top of them to act as a makeshift blanket.
"G'night," Stiles mumbled sleepily.
"Good night, Batman."
END FINAL CHAPTER