Title: Nest

Author: OpheliacAngel

Pairings: Sam/Cas/Dean

Genres: Romance/Family

Rating: Teen

Summary: Sam thinks that this is as good a time as any. After expressing his desire to invite a third member into their bed, Dean drags him into something that he admits he never quite saw coming.

A/N: Written for Day 3 of #queersamweek on tumblr, which is Favorite Poly relationship. Sorry it's late, this one was really difficult for me for some reason.

For a long time Sam has understood Cas to be Dean's.

It doesn't bother him at first, not really, partly because the angel did pull his brother out of hell and also because Dean needs something - someone -in his life other than Sam and the Impala, even if he never acts on that need. Sam doesn't know whether he's waiting for his own happiness or denying that it even exists at all, doesn't know whether he's waiting for Dean to make his move or for Cas to make one of his own.

From the first moment he met Cas he was awkward and stuttering, barely able to pull himself together. It's taken a long time to trust him and an even longer time to call him a friend, to call him family, but Sam's reasoned that he's reached that point long ago, and he just doesn't know what he's waiting for anymore. He's sick of thinking and believing that his brother has dibs on Cas, sick of waiting to see what he's going to do.

Sam doesn't blame Dean for loving Cas, just like he doesn't blame himself for loving him. He's waited for Cas to join their tight-knit community of family, and now he wants to give him the kind of love he gives to Dean.

One night, Sam gets sick of waiting and broaches the topic that's been on his mind for months with his brother. They're lying face to face in bed, chests and noses brushing they're so close, and Dean eyes are closed, his eyelashes so long, but Sam knows he's not sleeping.

"Hey, Dean?" He whispers in the near dark, running his thumb across Dean's forehead. He stirs, mumbling something, and Sam can tell he's irritated - Dean is never much for talking when they're lying in each other's arms after sex, as if he thinks it makes their cuddling more of a reality than it needs to be for him - but he laughs anyway, kissing the tip of Dean's nose.

If involving Cas in whatever they have would end up driving Dean away, or cause them to even lose a part of what they're worked at for years, then he would never go through with it. He knows somehow though that bringing Castiel into the fold will change nothing. He can only strengthen them.

"Hear me out for a second, jerk."

Dean huffs and opens his eyes, "This better be good, Sammy." Just as Sam expected he starts pulling away, despite the bed being so small he's close to falling out. Dean looks so small when he's spread out before Sam's eyes, bright hazel eyes opening and sleep-addled brain bringing forth adorable, half-murmured words, and he looks even smaller now for some reason. Beautiful.

Sam pulls him closer and runs his hands through his bed head. He stops after a minute, his face turning serious. "Listen, I think that maybe we should give Cas more credit than we've been giving him."

"Sam...," Dean whines.

"Hear me out, Dean. I think... I think that we should invite him."

And Dean definitely seems wide awake now. "Invite him?"

Sam runs a hand through his hair, trying to figure out how he's going to put this into words. He should have known that Dean would be like this, should have known there would be no easy way. "Yeah, like, into our bed with us. And don't look at me like that, Dean, like I don't know that you've been wanting Cas for ages. It's something that we both want, and if you're not going to admit to it then I am."

There's an uncomfortable silence between them then, it's not long, but it feels like ages to Sam.

"You and Cas?"

Sam takes note of the tone of his voice, realizes that Dean isn't angry or even trying to switch the subject. He's just trying to understand all of this and Sam can hardly blame him for that.

"Cas and us," Sam corrects.

Sam goes out for a run the next morning, even knowing it pisses Dean off to see him so energetic, up at six am every morning with sweatpants and his best running shoes on and ear buds in his ears, pumping a satisfying mix of pop and alternative music into his brain. He's quiet as he slips out of the bedroom, careful not to wake Dean; he needs sleep so much more than an early breakfast of booze and, oh yeah, more booze. He sighs angrily and jams the buds deeper into his ears. He can't blame Dean entirely, but he does wish that he would drink less and come out to jog with Sam every once in a while.

He can dream.

Dean seemed pretty empathetic last night when he brought up the idea of bringing Cas into their relationship, so Sam hopes he wasn't dreaming about that potential reality. He's willing to give Dean some more time, to talk to Cas, but he's not going to wait forever. A week sounds good, Sam convinces himself, it sounds fair.

He gets back an hour later, surprised to see that Dean isn't in the kitchen nursing a glass of his so-called medicine. He's worried for a second that Dean just up and left, uncomfortable with what Sam had proposed, but he decides that he wants to think better of Dean than that and ventures into the bedroom. Dean's there, piling and rearranging several blankets on the bed and settling several more on the floor on both sides of the bed.

Sam clears his throat, amused by Dean's strange behavior. "What the hell are you doing, Dean?"

"Oh, uh..." His brother blushes crimson, rearranging a particular blanket meticulously, picking at a thread. "Cas said he's scared of falling out of bed, so I figured this way he doesn't have to worry."

That doesn't explain the extra padding on the bed but whatever, if Dean wants to act odd then he can act odd. It also doesn't explain why Cas is suddenly using their bed.

Dean, seeming to be satisfied with the new arrangement, gets up, grabs Sam's arm and tries to pull him over towards the bed. Sam catches on pretty quickly and resists. "Whoa there. I'm all sweaty, Dean, let me at least take a shower first."

"Uh uh, you're not getting out of this now. This is what you wanted, Sam."

"What, me opening you up just after a jog?" He stares at Dean in confusion; his brother's not usually so horny in the mornings. The only explanation is that he hasn't had anything to drink yet. But then he looks in Dean's eyes and sees more than just lust there, there's hope too.

"No," Dean motions behind Sam and he turns around, eyes going wide when he notices Castiel. Castiel, whose hair is sticking up on one end and whose eyes are so big and ridiculously blue. Castiel, who is wearing one of Sam's shirts, which means it's a few sizes too big for his thin, all too human form but he looks amazingly cute in it anyway. Castiel, whose small nervous smile lights a spark in Sam that will never be extinguished.

The angel who he's been secretly in love with for all this time nods, "Sam. Dean has told me of your wish, your wish for the three of us to be together."

Sam steps forward, cups Cas' face with gentle hands and kisses him, a kiss that neither of them will ever forget.

Dean is rearranging the blankets on the bed again, fluffing the pillows, and once Sam leads Cas into the soft warmth he tackles Dean and tickles him until he's gasping for breath, his lips parted and forming a relaxed smile. They play around for a while, Dean or Sam dragging the angel into it when he ducks out out of shyness or uncertainty. They coax him into kisses until he's snaking an arm around Dean's shoulders and giving him one of his own, or lazily kissing his way up Sam's body, from the tips of his toes all the way up to his hair. Cas' fingers in his hair are what Sam has anticipated the most, the tingling at his scalp as a kiss lands there.

They lie in their nest, wrapped up in each other, limbs tangled, hearts open and souls on the mend.

FIN