A/N: Isn't mine. I just like to play in the sandbox. Feedback is love.
His knuckles sting. It's not a foreign feeling by any means, and these days, everything stings, but it's significant. He imagines for a moment that he could hear something crack when his fist met Dean's jaw.
When he straightens, chest heaving with the release of a few years worth of pent-up frustration and the effort he's exerted at swinging hard enough to break Dean, there's a thin trickle of blood at the corner of Dean's mouth and a purpling place that's already bruising.
The rage in Dean's eyes is dark, but Sam doesn't see - he's focused on the blood. Their blood. Winchester blood.
And it's Dean's own fault, really, because he was the one that instigated the detox in the first place. Maybe, after days of no blood at all, he doesn't care if it's human. Maybe, after days of no cocaine, anything that's white and powdery is good enough.
The philosophy is broken and he feels more than a little arrogant proclaiming it, but there's this palpable tension stretched between them and he's exhausted. Ruby said his appetite was getting bigger - it's just that, nothing else.
But the sight of the glistening, fresh trickle sends shivers up his spine.
When Dean finally open his mouth to speak or snarl or curse him (he isn't quite sure and he hasn't been paying attention) there's blood on his teeth. In his mouth.
Sam hates how he's become a creature of impulse.
He moves forward and Dean flinches back like he's going to hit him again, and maybe Sam is (maybe then he'd get blood on his knuckles and he'd lick them clean. It'd be glorious, the tang of iron and salt and something deeper, older). No, this is far worse than any physical blow.
Before he can reason himself out of it (because there is no reason now, he's abandoned it for lust and desire and the rush of red-black over his tongue), he's sucking at the line of blood from the corner of Dean's mouth. He likes to think that maybe Dean is too shocked to react as he laps at it, licks and sucks and works his lips to deepen the bruise that's already forming there.
And then his brother's head jerks back, away, and he just stares with an expression that speaks of disgust and betrayal. He stares like he doesn't know who Sam is. What he is. It stings something deep inside that Sam hadn't accessed in a while; Ruby lied to him, said he wouldn't have to hurt anymore if he did this.
It's immaterial.
"Shh," he supplies, crowding Dean backwards until he's pinned against the wall. Dean could get away if he wanted, maybe. He used to be able to.
The chandelier shakes dangerously, creaking with the effort.
Sam lowers his head and catches Dean's mouth again, sucking more than kissing, biting to get his brother's mouth open before he's diving inside. Blood and saliva, slick, wet heat and the forceful response from Dean's tongue. He's fighting Sam's battle now, not one of guns or knives. The only way he knows how, and for the first time Sam second-guesses himself; maybe he is keeping Dean there with more than just his body.
After straining the thing inside and keeping it from its source for so long, it's spinning out of control. Fast. Dangerous. Sam plunders Dean's mouth without any technique or gentleness; he isn't trying to be romantic. He wants every last drop of what Dean's got, the metallic slide of it over his tongue and down his throat.
It burns in his stomach, mixes with the demon blood that's already there from the rest of the day. It's like being kicked.
But the taste; it's glorious, salty texture and he can't quit now, not if he tried.
Something in the act of it triggers a response in him: maybe it's the blood itself or the fact that almost every time he's ingested it he's fucked Ruby, but it doesn't matter now, because it's happening. He's hard enough to pound nails and it's really fucking inappropriate. The whole situation is inappropriate.
He pulls back from Dean's mouth and presses his bloody lips to the sensitive skin of his throat. "Touch me," he coaxes, pleads with Dean. He won't look up, won't look at what's going on across his brother's face. The emptiness there would be painful.
"Sam," Dean warns, voice low and dangerous and sharp.
"Do it," Sam growls in response. "It's your fucking fault for putting me away. Do it!" He doesn't know anymore if he's directing Dean's movements or if he's doing it of his won accord, but his fingers slip beneath Sam's layers to skin, blindly down past the elastic waistband of his boxers. It's not gentle; barely even good as Dean strokes him. Mechanical.
His brother's switched off for the moment, but Sam couldn't care less. It doesn't have to be good, because when he gets hold of Dean's mouth again and sucks more blood out of the open wound there (where Sam split his lip; he tongues at the place it's broken and can feel the way Dean's holding back the whimper of pain), it sends him tumbling over the edge.
Sam bucks, biting down on Dean's lip so hard it draws more blood, and the taste of it prolongs the orgasm, draws it out until he's wrung dry and still shaking from the aftershocks. He collapses against Dean, boneless from the deep-set exhaustion despite the need to move, to get off of his brother and go with Ruby to see the member of Lilith's entourage. His lips still move, red and aching, over the new blood pulsing steadily from the bite-wounds in Dean's lip; he can't stop, too far down the deep tunnel of addiction and wrongness.
If it was Ruby's blood that made him what he is, surely Dean's blood - the blood of a righteous man, someone undeniably human and maybe even a little divine - will make him human again.