A/N: For anyone who's ever wondered what I do when I can't sleep... well, now you know. I write smut on my ipod touch. Warning for explicit sex, threesomes and sort-of incest, please don't read if that squicks you.
Cas knows Sam loves him like this – over-sensitised, trembling, loose, already fucked open and on his knees with Dean's come dripping slowly down his thighs. "Sloppy seconds," Dean calls it, with a low laugh, and Cas laughs too, until Sam thrusts particularly hard and the breath for it is driven out of his chest in a low, keening whine.
He drops to his elbows, forearms trembling too hard from holding himself up, first for Dean and now for Sam. His knees will ache the next morning, and there'll be bruises on his hips for days, large pale ones with darker, smaller marks in the middle. Dean likes to cling too tight, to bite, to scratch, like a cat marking its territory. Cas doesn't mind in the slightest - if that is what the hunter needs to convince himself that Castiel, that this, is not going away any time soon, then the angel will give it to him, gladly. He'll give everything, to both of them, gladly and unreservedly, just because they're them.
Another thrust from Sam and he's groaning, his voice one long, rough gasp of 'please' and 'need it' and 'too much' and 'more'. Dean rumbles approval at the vocal surrender, hand trailing lightly through Cas's hair, and although Castiel can't see it he can feel Sam's grin against his spine when the hunter leans down and kisses between his shoulder blades. Sam is always the gentler one, with soft kisses and light touches that leave Cas a breathless mess, desperate for Dean's less teasing touch to finally give him what he wants.
When Sam angles his thrusts slightly and finds Castiel's prostate, the angel near about wails, mouth and eyes opening wide and hips stuttering back against Sam's, desperate for more. Dean laughs at the noise, and Sam groans, reaching around to form his fingers into a loose fist around Cas's cock – he's already half-hard again, unable to help it. Sam's touch is too much too soon, he's too sensitive, and squirms away from the bright pleasure-pain of it with a low whimper.
Dean takes advantage of his open mouth, hooking two fingers inside to stop Cas from closing it. He's got no way of muffling his voice, of holding back the needy noises he's making now – the little pants and groans as Sam slows to an unbearable pace, fingers stroking far too kindly along the aching length of his cock.
He squirms away from the touch, pressing backwards, until Sam's so deep in him it feels impossible, until there's nowhere left to move back to. Dean growls appreciatively at the sight, licking his lips, and Sam lets out a low, stuttering breath at the feel of the heat all around him. He bends down and winds a hand in Cas's hair, pulls his head up and whispers, "so fucking beautiful," into the angel's ear like he's saying, "I love you."
Castiel whimpers. "Please," he begs around the fingers in his mouth, the word coming out broken and half-formed, damp with saliva, "please." Sam doesn't need to ask what that means, just starts moving again, slowly, letting the angel rock slowly between his cock and fist.
Dean watches them both with heavy-lidded eyes, approval written in his dark, blown pupils and slack jaw. He only stays that way for a moment, though, because then surprise takes over when Cas lifts his head away from the fingers hooking his mouth open and starts licking at the mess still left around Dean's cock, tongue soft and damp and worshipful.
There's a moment of silence, filled only with the sound of flesh on flesh and damp, heavy breathing. And then Sam notices where Cas's mouth has gone and he groans, hips snapping forward with more urgency, like he can't help himself. Cas smirks against the inside of Dean's thigh, and trails damp kisses down the soft length of him with evident satisfaction at this new pace. Sometimes the boys underestimate how clever he can be, how he knows exactly what to do to get what he wants, and he rather enjoys reminding them.
Cas comes first. The combination of the hand tugging insistently at his cock and the heavy, blunt pressure on his prostate win out over his body's achy reluctance to release so soon after the last time and he comes with a howl. His arms and knees buckle, the pleasure of it so sharply, overwhelmingly insistent it's almost pain, bright and hot and glorious.
He collapses, Sam's hands on his hips the only thing keeping him off the floor as he rides out his climax, gasping helplessly against the rough motel carpet. And then there are arms around him, pulling him up and cradling him to a warm, solid chest, soft words of encouragement being murmured into his ear.
"So fucking gorgeous," mutters Dean as he holds the angel through Sam's increasingly erratic thrusts. "So good, so perfect, ours, just ours."
Castiel whimpers back, "too much, too much," because it is, because he can't breathe through the heaviness of it all, but he refuses to say stop. He never wants it to stop, never wants this hot, overwhelming rightness to end.
Sam comes moments later with a low, wrecked groan, and aching fullness of it as the hunter presses all the way in and fills him up wrings another soft cry from Castiel, voice breathless against the side of Dean's neck as he starts to tremble.
Sam stays there for a moment, breathing heavily and rolling his hips lightly forward and back as he tries to drag out the pleasure out a little longer. He pulls out with a wet, almost obscene noise, and Cas groans at the emptiness of it, at the exhausted looseness of his whole body, at how everything aches and sings at the same time.
Between the two of them, they hold him up, Dean with his arms under Castiel's and Sam with his arms around the angel's waist, cradling him between them on the hard floor. He sways, leans forward against Dean and arches his shaking shoulders up as Sam peppers them with light kisses.
They stay there for a while, Dean's lips on his forehead as he whispers, "beautiful," and Sam's lips at the nape of his neck as he breathes, "perfect," two sets of fingers carding through damp hair. Cas wants to return the gesture, wants to kiss and touch back, but he can't find the energy to move right now. He thinks the Winchesters understand that, though. With all their gentle touches and soft words focused on him right now, this time is about him, no one else. This is their way of saying, "thank you for what you give us, for what you let us do," because they'd never find the words to say it otherwise.
Eventually they pick him up, body loose and relaxed and half way to sleep, and clean the drying come off of him and themselves, carry him to the bed and put him in the middle. Sam lies on his right, hip pressed against Castiel's, and Dean on his left, one leg thrown across both of the angel's to nudge against Sam's knee. The brothers' hands rest on his stomach, fingers tangled together just above his belly button.
"Look at you," whispers Sam fondly, pushing the dark hair back from his forehead and out of his nearly closed eyes, and Dean adds, "sleep," and tracing curious patterns across his collar bones. Sam laughs, nuzzling against Cas's neck, and kicks Dean lightly.
"If you tell him to sleep, then let him sleep," he complains quietly, "don't go and distract him." Dean sticks out his tongue.
Castiel follows the exchange with closed eyes, smiling, bruised and reddened lips curving up slightly at the corners. He breathes out a slow, tired sigh, burrowing further into the mattress, loving the warmth from the bodies on either side of him. "I love you," he murmurs, voice little more than an exhaled breath, but both the hunters stop their quiet bickering instantly at the words.
"Love you too," they reply, almost with one voice. Castiel feels the fingers knotted on his stomach squeeze each other tighter, and knows they were not just talking to him. He nods, satisfied, and lets himself drift off to sleep to quiet promises that they'll both still be there when he wakes up.
He doesn't know what he's done to deserve this, but now he has it, he's never letting it go.