The story of Adam and Eve's sons is simple enough in the telling. Abel is slain at the hand of his brother, because Cain is envious, covetous, spiteful, stained with inherent sin.

Dean thinks maybe there is more to the telling of this story. Maybe Cain didn't kill his brother out of spite. It's just misguided affection. He knows the hope of wanting to watch his brother live and the desire to spare him the pain of a harsh world.

Dean looks at Sam, and sometimes his hand itches to reach for his knife. Not to carry out his father's dying request that he kill Sam should the darkness consume him. No, this urge is to spare his brother the pain, the stains of sins that Dean is so close to committing.

It's been weeks since Sammy was possessed. Still the pain in Sam's eyes when they finally decided to talk about it is enough to break Dean even more. Dean doesn't have much left to break, but what's left belongs to Sam. He's resigned to this fact.

He is the Cain in this story, and Sam… Sammy is his beloved Abel.

His breath catches in his throat as he lets it out slowly, his steady gaze unwavering as he stares at his brother. Sam is sleeping, his back rising and falling with every breath, a slight snore catching on every third, sometimes fourth breath, and Dean blinks for a moment and feels warmth slip down his left cheek.

He lifts a hand and brushes away the tear, draws silently closer to the bed and crouches down. He looks at Sam's face, fighting with his hand's desire to reach out and brush the hair away from his brother's face.

His tongue slips across his lips, and then he's reaching back, his hand slipping under his pillow, closing around the hilt of his knife.

He closes his eyes, takes in a deep breath, and when he opens them, his gaze locks with Sam's. He swallows thickly, caught and exposed. He wants so much for this to be quick. Sam would go in his sleep and Dean is determined to follow. That is how it's supposed to be.

Sam's breathing is steady as his eyes shift and he watches Dean draw the knife, and sees the blade shine in the moonlight. He shifts, rolls onto his side, and then Dean rolls him over the rest of the way and straddles him with a hunter's grace.

The blade of the knife is at Sam's throat and Sam makes no move to resist. Dean looks down at him, more tears slipping silently down his face as he presses the blade dangerously close, almost to the point of breaking skin.

His chest is heaving and he leans back, his ass against Sam's thighs. He let's his head fall back and pulls the knife away, lets it drop to the floor, and then he leans forward, his hands bracing him. His head slumps forward, his chin pressed against his chest, and he's trembling.

"Oh God, Sammy… Why? Why is it like this? Why do older brothers have to kill the better son to redeem them and damn himself? I can't save you, Sammy. I just… I can't," Dean whispers.

Sam sighs. "Then end it. I get it, Dean. It's okay. Just, make it quick."

Dean shakes his head firmly. "No. It's not about the Demon, or Dad's stupid fucking request or order or whatever the hell it was. This is about you and me. This is about us! I can't save you, Sammy. I can't save you from me."

"Dean?" Sam asks, his tone filled with worry. "What is this, man? What are you saying?"

Dean lifts his head, let's his eyes fall closed for a moment, and when they open again he sees the questions in his little brother's eyes. He lets his fingers trail down Sam's jaw and leans forward.

He doesn't stop until his lips are pressed against Sam's and he feel's his brother's body stiffen beneath him. He shifts and his crotch meets with Sam's, and he's achingly hard.

Sam jerks beneath him and pushes him away. He's wild eyed and gaping, and Dean wishes he had the knife again so that he could end it, only he'd be sending the right brother to hell; he'd be sending himself.

Dean tries to twist away, but Sam's hands are firm on his biceps, and Sam gives him a little shake until he looks at him.

"Dean, what the hell is going on?" Sam demands, his voice steady and oddly quiet compared to its usual loud bass.

He wishes he could turn away, but Sam holds his gaze and Dean swallows thickly, shifts and lowers himself, aligning his crotch with Sam's to create some friction, because without it he feels that he might just die.

"This is the darkness coming for you, Sammy. The darkness is inside of me, and I can't fight it anymore. I've wanted you all my life, watched you grow, taught you, held you, cleaned up your God damned scraped knees and puke, kicked all of the bullies' asses, told you about girls, watched you jack off for the first time, kept silent when you walked out the door and left me and Dad, dragged you back into this hell. I've wanted you. I'm a selfish fuck, and all I want is you, this, now. Can't get enough," Dean whispers, his voice husky with lust, and Sam lets out a stuttered breath at the wash of emotions in his brother's eyes.

Dean shudders when Sam rolls his hips up and into his crotch, and Dean's eyes widen as he stares down at Sam in surprise. Sam is hard through the cloth of his boxers, as hard as Dean.

Sam's hands shift, one hand beneath Dean's shirt, skimming up his chest, his index finger brushing over a dusty nipple teasingly, while the other hand finds the back of Dean's head and drags him down for another kiss, a real kiss.

Lost in the smell, touch, and taste of Sam, Dean doesn't really care that he is committing an unforgivable sin. Fuck anyone that says this is wrong when his body, heart, and soul are screaming that it's right. Oh so right. As his lips move and open against Sam's mouth he lets go of the darkness, feels it wash through him, and it's forbidden, but right.

Cain was wrong. Dean knows this for a fact. Killing your other half isn't necessary. Giving in, and claiming the shadows is more rewarding.

Killing spares no one if you love someone this deeply, and Dean is breaking as Sam's hand closes around him, pulling him into a carnal and sin filled heaven. Yes, Dean is breaking, the knife is on the floor, and this time Cain doesn't kill Abel.

End.