Summary: Soulless Sam gives Dean what he wants, sort of. For a price.
Warnings: Non-con (for the real Sam), dub-con, unrequited love, dark, angst.
Imagine Soulless Sam trying to fuck an underage girl and Dean steps in. Sam tells him to back off, but he won't, keeps bothering him about jailbait and a bunch of other things that don't interest him. He sneers and says, "what, you offering, big brother?" Dean pales and that gets his attention. The way Dean can't quite look him in the eye after that when he tells him "let's just get the fuck outta here." The way Dean flinches when he stands too close and breathes on the back of his neck. He should have thought of this sooner.
Back at the motel all Sam wants to do is watch his brother break. "I know why you stopped me and it's not really about that little bitch. You love him. That Sam knew it, could feel it in everything you did for him." He pauses, smirks a little as Dean shifts uncomfortably on his bed. "He doesn't love you like that, Dean. Never did. That's all you. I don't have a soul, but at least I'm not sick like you. Tell you what though: I'll fuck you right now. I'll fuck you whenever you want. Only thing I ask is you drop the soul searching thing. I don't want it. And deep down I know you don't want it back either."
Dean acts angry, but Sam can see his cock's already hard. Dean's weak, so fucking weak. When Sam undresses in front of him, shows off his length, Dean can't take it anymore. He moans. "Okay, okay. Just. Get over here."
He fucks into Dean viciously, hard quick thrusts that have him hiding his face in the pillows, but it doesn't cover up his cries. Whether it's from the lack of prep or something else Sam doesn't know. And of course he doesn't care.