It begins with Stiles showing up soaking wet, clothes plastered to his freckled skin, at Derek's front door. When he rambles out a half-assed story of getting into a fight with Scott and not wanting to go home and be alone in his bed for this one night. When Derek opens the door wider and leads him to his bedroom, ignoring his better judgment. With Stiles watching Derek intently as he trades the dripping wet t-shirt and soaked through jeans for a dry tank top and soft pajama bottoms that hang loosely over his hips. With Derek crowding Stiles against the tall dresser because he can feel Stiles' need leaking out of his pores and filling every inch of the room with want. And Derek thinks that just this once he can want, too.
He pretends as if Stiles hasn't used this same exact tactic on previous occasions. Pretends that he hadn't turned him down because Derek wanted too much that Stiles wasn't ready to give him, and probably never would be ready to give him. Because Stiles needs this one night. He had a fight with his best friend and he turned to Derek because he needed this. And for as much as Derek wanted, the amount of Stiles that he needed terrified the shit out of him. So yeah, it begins with heated kisses and backs pressed too hard against plain white walls. It begins with rough, untamed movements towards a mattress that was hardly ever slept in. With Derek draped across Stiles' back as he moaned his name. With Stiles' hands gripping Derek's sheets and screaming his name as both of their orgasms rip through them.
But it doesn't end there.
The days that follow don't feature any major changes but they do at the same exact time and Derek doesn't know what to do about it. Stiles still barges into his home, uninvited and vibrating with energy, and throws himself on his couch and eats all his junk food. "Seriously, dude. Do you even own anything to eat that isn't microwavable?"
Stiles still throws ridiculous pop culture references that he knows Derek will never get at him. "Man, anyone ever tell you that your stoic silence and lack of any outward emotions resemble the angels from Supernatural? Because, let me tell you. You would make a fucking fantastic Castiel, well, from like season 5 to season 7 obviously".
None of that changes. But Derek wishes it would. He wishes Stiles would show up at his door with leftovers because he knows that all Derek eats is microwaved shit. He wishes Stiles would bring over his collection of Supernatural DVDs so that Derek would understand all his silly pop culture references. But that never happens.
What does happen is Stiles showing up at 1 am and pushing his way through the door to attack Derek's neck with kisses. His hands frantically searching for the buttons on Derek's jeans before they even make it to the stairs because he can't wait. What does happen, is Stiles begging Derek to fuck him senseless into the mattress when he needs an escape. And Derek does. He does it every single time because he wants all of Stiles. He wants the sex, he wants Stiles to still be there when he wakes up in the morning, he wants to go on cheesy ice cream dates with Stiles at 11pm because that's just what couples do. But he and Stiles are not a couple. Not even close, and he doesn't fool himself into thinking that they are. Sometimes Stiles needs an escape and Derek provides him with one. Because they trust each other; after everything they've been through together, God knows they trust each other with their lives. But even though Stiles wouldn't hesitate to put a bullet through a man's chest for Derek, he doesn't love him. Not like that at least. And Derek's fine with it, honestly. So he wants to live a romantic comedy with Stiles, no big deal. He'll take whatever Stiles will give him. Because even just a part of Stiles is enough to fill the deafening thoughts that bounce around in his head. Even if it's only for a little while.