Sam's "hand thing" for the hallucinations no longer working AU.
They're back at the motel. Dean can tell Sam is still antsy. Sam keeps insisting he's fine. He's very visibly not, but he says "g'night dean," and gets into bed and faces away from Dean and makes it Very Clear he's not gonna talk about this.
Dean tries to stay awake, he really does. He knows Sam isn't okay so he runs through everything he could do or say and he's fucking exhausted and nothing sticks and next thing, he's out like a light, sleep restlesses as he's in and out of consciousness because he's worried.
Sam focuses on Dean's breathing. He focuses on his own breathing. Lucifer is laughing at him. Pestering him. Sam feels flames lick at his heels and forces his breathing to stay as quiet as he can. He focuses on Dean's breathing. He tries to match his breathing to Dean's. Dean's his lifeline.
Dean finally seems to fall asleep. Sam tries to continue the act but Dean's asleep and who is he even pretending for? They both know Sam's lost his goddamn mind.
Sam rolls onto his back and looks over at Dean. He can barely see Dean through the flames. Lucifer laughs cruelly and he can't hear Dean breathe anymore. Sam's breathing has grown erratic and something in him shrivels and curls in further on himself because he can't see or hear Dean anymore and it's too dark and there's nothing to distract or pull Sam away from the hallucinations anymore.
He knows Dean is still there. He knows. He knows that he's with Dean in some fucking motel but then he feels the ghost of Lucifer's breath— a breath he doesn't even need to breathe— on his neck and Sam launches out of his bed, practically out of his own skin.
That wakes Dean with a start. He asks if Sam is okay and Sam fucking whines and Dean watches Sam worry his bottom lip as he begins pacing, running his hands through his hair, pale as a ghost. Dean calls out, "hey. Hey! Sam!" And he's harsher than he means to be, louder than he means to be, but Sam's head snaps towards him, eyes wild and they just. Just stare at each other for a second.
Sam hears Dean and suddenly everything grounds back into place. For a moment, one blissful moment, there's no flames, no Lucifer. He's right back in the motel with Dean and it's the middle of the night and he's just so tired and wants to curl up and fucking sleep.
And then he feels fingers run up his back. Delicate, deliberate, disgusting. "I can't sleep," Sam blurts, and he's looking at Dean, a pleading question in his eyes.
Sam hasn't given Dean that look in years. Since Sam was a kid with nightmares and way too old to be sleeping cuddled up to his big brother. But Dean could never deny Sam, not when he looks at him with those pleading, puppydog big brown doe eyes. So he just sighs like he hadn't drifted off thinking how he could suggest this exact thing without it being weird and pulls the covers aside and Sam practically flies from where he is across the room into Dean's arms.
Sam gets as close to Dean as he possibly can. Face buried in his neck, arms and legs fucking clinging to Dean like he's drowning. And it all comes pouring out. He's shaking. He's trying to not cry. He still feels the ghost of Lucifer's breath on his neck, right up until Dean pets a hand through his hair, down his neck over the spot, and it's gone. Fingers tailing down his spine evaporate as Dean rubs his back. Lucifer's voice becomes a distant, almost indistinct murmur as Dean whispers and coos soothing nothings into his hair.
It doesn't fix everything, but fuck it does help.
Dean becomes even more of a crutch. Every time things get to be a little Too Much for Sam, Sam finds himself instinctively reaching for Dean. Which can be a little weird when their posing as whatever authority the job needs, but whatever.
Dean knows this isn't a permanent solution. They both know it. But it does something to him. Knowing that despite everything Sam still reaches to him when he needs help. Him, not anyone else.