"Y'know, I don't see why I have to go to bed this — "

"Really?"

"Fine," Sam says again, giving up. It was worth a try.

"Good night, Sam," Cas says.

"Cas,"  Sam says, turning around from where he is headed up the stairs, "will  you come visit me again sometime? I mean, not just to see Dean?"

"Certainly."

Sam smiles at him. "Awesome. G'night you guys."

"Night, Sammy."

After  washing and brushing his teeth and hollering one more "G'night" down to  the living room, Sam drifts into a fitful sleep. He's not asleep for  more than two hours when he wakes up from a bizarre nightmare in which  his teacher Mr. Bensman has been turned into a devil and is chasing him  around with a pitchfork. He does the first thing he always does in  situations like this, which is to find Dean and crawl into bed next to  him.

Only when he gets to the end of the hall Dean isn't in his  bed. He glances at the clock and knows Dad won't be back for at least  another half hour, and gets annoyed that Dean can stay up and he can't.

There's  a light on downstairs, and from the glow Sam knows it's coming from the  kitchen. Dean is probably eating again, as usual. He decides to go help  himself to half of whatever it is he's snacking on.

He's halfway down the stairs when he sees it.

Cas  is on the couch, his head tipped back against the cushions, eyes  closed, mouth open. He's shirtless, as is Dean, who has his face pressed  against Cas's chest.

Another step down and Sam can see that Cas's  jeans are undone, and that Dean has his hand slipped inside them. He's  pumping his hand slowly up and down while he sucks at Cas's nipple. Then  Dean moves his lips to Cas's chest and kisses his way up to Cas's jaw.  Little moans and sighs are coming from Cas's open mouth.

"Oh my God," Sam gasps.

Both Dean and Cas startle and sit up on the couch.

"Oh fuck!"

"Oh my God!" Sam yells now, running back up the stairs. "Oh my God, oh my God, oh my God!"

"Sammy, wait!"

But  he doesn't stop running until he gets back to his room and throws  himself on his bed. He can't believe what he just saw. He's angry and  hurt and he can't think straight. He doesn't try to prevent the tears  from welling up in his eyes.

Dean finally walks in after a few  minutes, tucking his shirt back into his pants without looking like  that's what he's doing. He sits down next to Sam on the bed and doesn't  say anything at first.

Sam is sniffling and having a hard time trying to wipe his face without Dean noticing.

"Sammy. Lemme try to explain, all right?"

"Explain what? That you weren't on the couch with your hand down Cas's pants?"

Dean flinches. "Well — "

"Is  that why you guys have been ignorin' me, why we haven't been spendin'  any time together? You didn't want me around, is that it? Because you  two are, like, boyfriends, or somethin'?"

"It's not like that, Sam — "

"What is it like then, Dean? You're not boyfriends or you didn't have your hand down Cas's pants?"

Cas  walks up and stands outside the doorway. His face is stricken and pale,  and he leans against the doorjamb, probably more for support than  anything else.

"We weren't sure how to tell you, Sam," Cas says. "We were afraid you —"

"Would  freak out?" Sam asks, the hot tears streaming down his face. He doesn't  bother to try and hide them. "Like the way I am now because you've been  keepin' this secret from me for the past year?"

"We thought you were too young," Cas answers.

"Really?  You used to tell me everything, Dean," Sam says while turning to his  brother, hurt in his voice. "When you had bad dreams about the fire that  killed mom, when you faked Dad's signature on your report card, even  when I was in first grade and you were in fifth and that bully kept  beatin' you up, remember, you would tell me how scared you were?"

"I remember."

"Now you think I'm too young to hear about this? This?  I knew somethin' was goin' on between you, but I didn't know what it  was. I even tried to talk to you about it. You didn't want to."

"I'm sorry," Dean says. "I didn't know what to tell you."

"The truth would've been nice," Sam says angrily. "I'm 12, not stupid."

"Please try and forgive us, Sam," Cas says. "We didn't mean to hurt you. We just weren't sure you would understand."

"Two guys together you mean? Katie Delacroix has two moms. It's kinda different but not that different."

"But it's your brother," Cas says, looking over to Dean. "It's not quite the same thing."

"I  can tell Dean has been happier than I've ever seen him — even if I  didn't know why — which means I know you're good for him, Cas. I want  him to be happy. That I can understand. But lying to me? No. That I  don't."

Dean puts his hand on Sam's knee. "Sammy — "

"I think I want to go back to sleep now," Sam says, rolling over onto his side.

Dean  sits there and doesn't move until it's clear Sam doesn't want to talk  anymore. He wants to go back to sleep and forget that his brother and  his best friend have been kissing and touching and doing who knows what  to each other for the past year and not bothering to say a damn thing  about it.

"All right, man. I'll see you in the mornin', okay?"

But Sam doesn't answer, so Dean closes the door silently behind him.