*bites lip* yes yes hnng. Thinking about the first time Sam walks in while it’s happening, the first time he sees his brother bent over in a bathroom or in a dark alley behind a bar, the first time he sees Dean with flushed cheeks and an open moaning mouth, eyes glazed over in bliss as he gets roughly fucked. They lock eyes, and Sam takes way too long to look away, way too long to leave, and he knows this, but he can’t stop watching. They don’t talk about it afterward, of course.
Imagine this happening while Sam and Dean are in one of those “it doesn’t count as crossing boundaries, this is so normal” stages where they’re doing shit like jerking off in motel rooms at the same time, fucking women in their separate beds at the same time and locking eyes across the room.
After Sam sees Dean getting fucked in that bathroom, he can’t stop thinking about it, can’t stop thinking about his brother’s ass getting filled, and the next time they jerk off together, Sam asks Dean to turn around.
Dean’s hand goes still on his cock, and it gets so very quiet in the motel room. Sam’s heart skips a beat, and when it starts back up, it’s pounding, pounding, pounding because what if he fucked this up completely? They’ve never talked during these jerk off sessions at all, much less like that. It’s always muted grunts and groans, and Sam is always fighting the urge to say Dean’s name but he doesn’t ever do it.
They’re both breathing heavy and staring each other down, and it feels like an eternity before Dean slowly moves across the mattress and gets on all fours, starting to touch himself again. Sam starts up again too, and it’s indescribable, seeing Dean do this for him. All restraint goes out the window, and Sam forgets about that unwritten rule of silence. He can’t stop talking now.
“Can’t stop thinking about it, Dean, you just—fuck, you just taking it like that, bent over and just—fuck, spread your legs, please I need—“
Even in this state, nothing but hormonal drive running the show, Sam still has a bit of self preservation. He can’t actually say that he wants to see his brother’s asshole, but Dean spreads his legs just like Sam begged for him to, and there it is. It turns Sam on so fucking much, looking at Dean’s hole and imagining it filled, a cock driving in and out, making it puffy and red and used, and Dean just—in love with it, blissed out and begging for more.
But it also makes Sam feel possessive and crazy, hating that he isn’t the one dragging Dean behind a bar to rail him against the building. It fucking should be. Sam fists his cock faster and thinks about walking over to the other bed and coming all over Dean’s hole, smearing the come over it, pushing it inside with his fingers, marking Dean up from the inside and the outside, leaving pieces of himself inside Dean for the next time someone fucks him.
Sam comes so fucking hard, it almost hurts.
They don’t talk about it afterward because of course they don’t.
Dean mumbles something about needing a shower, unable to meet Sam’s eyes, but the next time Dean wanders off to get fucked in a bar bathroom, he makes meaningful eye contact with Sam before he leaves.
“I might be a while,” Dean says, staring back at Sam like he’s making sure he’s being understood before he saunters off to the bathroom.
How can Sam take that as anything but an invitation to follow? An invitation to watch and bring the image back to the motel with him.
