He wonders if it's a complex at first, this thing he and his brother have. Sam fell for the demon(quite hard he muses sadly) and now it seems that Dean's fallen for the angel. They stopped the apocalypse and Castiel should have left, should have gone home. But he didn't. Cas is still here, offering Dean and Sam counsel on whatever creature they're facing this week, and that's when Sam suddenly sees it.

At first, he thought Dean's love was one-sided; he thought that's why Dean hadn't made his move already, but then Sam sees Castiel smiling at Dean like he's the only person in the world and then Sam's just confused. If Cas likes Dean, why hasn't Dean done anything? His brother isn't that oblivious so Sam asks casually over dinner one day why Dean and Cas haven't had kinky angel sex already. Dean, needless to say, is shocked and begins choking on the steak Bobby had cooked; afterwards, Dean disappears, avoiding the situation altogether.

It's been a few months now and Castiel still shows up, his visits getting longer and longer; Bobby's in the middle of setting up the guest room when Dean and Sam get back from a hunt.

"What are you doing?" Dean asks, curious at first, but then Bobby tells him the room's for Cas and Sam remembers that face; his brother makes that face when he's hurt or when he's about to get hurt. "Why bother? He'll be leaving soon anyway." Sam asks what he's talking about and Dean looks away, his gaze locked on the wall. "He's an angel, Sam. Sooner or later, something more important's gonna happen and he'll leave like everybody else."

He's already in his room by the time Sam recovers and Sam's heart is breaking all over again. He moves towards Dean's door, but then Castiel bursts in and storms past him, throwing Dean's door open; Sam looks past Castiel's body to see his brother move back, but then Cas pulls him close and kisses him, a combination of rough and tender. If it weren't Cas and Dean, Sam might have thought it hot; now he just thinks it's cute(but he won't tell Dean that).

Cas pulls away, leaving Dean speechless and a little confused; his brother is open and vunerable and Sam really hopes the angel says the right thing because he's tired and he doesn't particularly want to kick angel ass tonight.

"Cas, this-" Dean swallows and starts again. "If you're gonna leave-"

"Dean, I have no intention of going anywhere." Cas smiles sweetly and then pushes him onto the bed. "And you'll be lucky if you leave this bed."

A little too much information. Sam quietly closes the door just as he sees Castiel begin pulling off Dean's clothes and breathes a sigh of relief. Now that that's taken care of, Sam can stop worrying about his brother and get some sleep.

Two hours later, Sam's staring up at his ceiling, listening to screams and moans; every half and hour or so, the lights will flicker and by the second round, he realizes that this is Cas's fault and he'll groan in frustration. Bobby sleeps on, snoring loudly and Sam glares at him, wishing he had done the smart thing and invested in a pair of ear plugs.