Stiles slept the way he lived: constantly twitching, eyelids fluttering, unable to stay in the same position for more than an hour before rolling over or curling up or stretching out. More than once Derek woke up to Stiles hooking a leg around his own, even when the rest of him was curled in a ball under the sheets on his side. Derek was used to it. He hardly ever woke up anymore in the night.
But sometimes, Derek just liked to watch, to stare as long as he wanted. He liked to watch the way the full moon played over Stiles’ face, how his eyelashes cast tiny shadows on his cheeks. He’d let his fingers glide over Stiles’ bare stomach to feel the muscles moved in tiny jerks as he dreamed. He liked being able to wake up in the morning and glance over to see Stiles in his bed, even more than he liked the way his clothes always seemed to be just a little too loose for the man.
And more often than not, Stiles was in Derek’s bed, or in his house, or just generally around. Derek would ask him to move in if he hadn’t pretty much done so already. The last time they’d been in Stiles’ room at the Stilinski household, his closet was more than half empty and the usual clutter of books strewn across the floor was down to a small, neat pile on Stiles’ desk, where his computer was suspiciously absent. There were still posters of bands and events from his childhood on the walls, but what struck Derek was that the room didn’t smell much like Stiles anymore. It didn’t smell like anything.
And then, when they got back to Derek’s house (because they’d only been there to have dinner with the sheriff and to pick up Stiles’ computer), Derek felt like he’d been slapped across the face in the best way possible. All he had to do was open the door to be met with a wall of himself and Stiles all mixed together until it became its own unique scent. He’d grinned from ear to ear until Stiles said his name in a question. He noticed he had still been standing next to the door, letting in the freezing air from outside (“Really, Derek, I know that you know I don’t run as hot as you do,” Stiles said for the millionth time.) So he shut the door and pulled Stiles to him and kissed him breathlessly, hardly able to stop grinning long enough to kiss properly at all.
“Everything okay?” Stiles whispered when Derek pulled back just enough to breathe.
“Yeah,” Derek said softly, still smiling. “It’s just…we’re us.”
Stiles laughed. “I know that, you weirdo. We’ve been us for two years.”
“No, I mean…the house—it smells like us.”
“Like you and me?” Stiles asked.
“No,” Derek murmured, pressing his lips to Stiles’ again because he couldn’t help it. “It smells like us. Together. Like we’re one person.”
Understanding lit up Stiles’ face and suddenly he was smiling as stupidly as Derek, standing there in the middle of the living room in the dark.