Still adding songs to Sammy iPod list, that's why it hasn't gone up yet.
Write them cursed by a demon to never be able to feel desire for anyone but each other.
Oh God that would just hurt so bad. And it would be angsty too because Dean knows about it but he never told Sammy because Sammy was only like, twelve when that demon decided to whammy them and he never thought for a second that the fucking thing would fuck over anyone but him, he was the one that shredded it's mate you know.
Anyway Dean knows what's going on and he's kinda more than a little tripped out over it but he gets used to picturing Sammy when he's with a chick and he even manages to stop almost throwing up after a few months of it and he just learns how to get used to it and file it away into that part of his brain that says he's never gonna be like anyone else.
Meanwhile Sam grows up and hits puberty and starts getting moody and freaking out because he can't sleep for more than a few minutes a time without having a wet dream about his big brother and it just makes him want to get the fuck away even more because of course it must have something to do with only ever being around Dean and Dad his whole life.
So Sammy runs away to college and becomes Sam and still has the dreams but has figured out that if he drinks enough or just stays awake until he drops from exhaustion he can't remember anything about them. After a while he meets a pretty girl named Jess who is smart and funny and pretty and interested in him and they date for a few months and the first time he goes to have sex with her he can't get it up until he imagines she's Dean.
Sam leaves immediately after and avoids her for a month until she literally backs him into a corner in the library and he freaks out so badly that he comes thisclose to physically shoving her away and she sees this and doesn't let him leave, she makes him talk and explain himself and he spins an elaborate lie about the Dad who used to beat him and his brother and all about how he doesn't want to get close to her because of history repeating itself and blah, blah, blah and she believes him and they take it slow.
They take it so slow and she doesn't mind not having sex and she loves him for him and she doesn't ask twice about things she knows he doesn't want to talk about and he knows in his mind that he loves her and one day he finds himself in a jewelry store and he plays it out in his mind and everything is fine and dandy and he thinks he might be able to make it worth with her.
And then three nights later he wakes up and Dean's on top of him in the living room.