Sam has always been considered the smart one in the Winchester family. He read Homer's Iliad when he was nine years old, and knows up to his fourteen times tables. Of course, in the Winchester family, none of this is considered as important as the fact that Sam can also assemble a rifle blindfolded in under sixty seconds, has memorised the ways to kill every major supernatural being his father had come across, and is adept at using the internet (something neither John or Dean have ever quite mastered) for research.

Yes, all three Winchesters know Sam is the smart one. So no one is more shocked than Sam when, one night in the shower when he's fourteen years old, he realises that he's been beating off to the thought of his brother sucking his cock.

Being the smart one, Sam wonders how this has escaped his attention before; because, thinking about it, this isn't the first time this had happened. In fact, Dean has been making his way unobtrusively into Sam's sexual fantasies for quite some time now... but he's been interspersed with tits and ass and all the things fourteen year old boys are supposed to think about while they're getting themselves off, and to be honest, Sam was always too busy enjoying the feeling of coming to really concentrate on what was getting him there.

He thinks about it now, though, as he steps out of the shower and begins to dry himself off. And he realises that tits and ass and, well, anything vaguely female, has slowly been replaced by Dean. Dean's magnetic eyes, and Dean's sensual lips, and Dean's hard, muscled body – Sam is suddenly nothing but thankful for the training regime their father imposes on the two of them.

Well, shit, Sam thinks. He's the smart one in the Winchester family, but you don't have to be a genius to know that wanting to fuck your brother isn't normal. And you don't have to have an IQ over 75 to realise that John Winchester won't like the idea of having any kind of homosexual in the family – it's all that marine crap – and Sam shudders to think what his father would have to say about incest.

Thinking the word brings Sam up short. Because incest has connotations of dirty, disgusting, wrong – and whatever this is that Sam's feeling for his brother, whether it's hormones or lust or true love, it certainly isn't wrong. In fact, he can't think of anything that's ever felt more right, and that's what really scares the shit out of him.

Maybe it's coincidence, or fate, or maybe someone, somewhere is just trying to fuck with him, but that's the moment that Dean bursts into the bathroom.
"Sammy! Take it to your bedroom, yeah? Some of us have bowels, dude!" Dean grins that grin at his brother – the one that gets him free desserts from waitresses everywhere – and before Sam realises what he's doing, he's got his mouth pressed up against his brother's, and his hand on Dean's hip.

Sam has always been the smart one, and if he'd stopped to consider his actions, he probably would have realised what would happen. But he didn't think; he just saw Dean, so sexy, so manly, and he went for it.

"Dude, what the fuck is wrong with you?! Are you fucking gay?" Dean practically shouts, tearing himself away from his little brother. Sam stops short, and turns beet-red as he realises what he's done.
"I- I just..." he stutters, trying to come up with an explanation that doesn't include the words I'm in love with you, but finding none. The look of pure disgust Dean gives him tears through his soul.
"Get the fuck outta here, Sammy," Dean spits at him. "I can't believe I've got such a twisted faggot for a brother!"

Shocked, Sam stumbles out of the room. If he'd looked, he would have seen that there was more fear than disgust in his brother's eyes – but he didn't look; he was too stricken by Dean's violent reaction.

In a daze, Sam wanders into his bedroom, thanking any higher being that might exist that this particular place has three bedrooms and not two. He flings himself onto the bed, and his hand hits something – the hunter's knife Dad gave him for his thirteenth birthday.

Sam is the smartest member of the Winchester family, and under normal circumstances, he's the first to launch into a diatribe about why self-harm is stupid, selfish, and attention-seeking. But Sam's just been rejected by the person who means more to him than anyone else – his brother – and so rationality is somewhat beyond him at this point. Slowly, he picks up the lethal-looking knife and, before he can really consider this course of action, draws the sharp blade across his tanned forearm.

The relief is immediate, but short-lived. Immediate, because this is pain he can focus on, and fix; it helps him forget the pain of Dean pushing him away, at least for a few minutes. Short-lived, because a new, more terrifying thought drifts into his head at that moment: John. His father will make him run laps until he vomits blood if he sees this.

Shit, Sam thinks. Shit, shit, FUCK.

Suddenly, he hears the door open. He doesn't have time to do anything other than throw his knife under the pillow before Dean moves hesitantly into the room.
"Sammy, I– fuck!" Dean exclaims, but quietly.

Sam is confused for a moment, before he thinks to look at his forearm, where blood is welling up out of the wound. Shit.
"Oh, Sammy," Dean is whispering now, and Sam could almost swear there are tears in his eyes. "Why would you do this to yourself, Sammy? Here... let me help."

He grabs the slightly damp towel from where Sam dropped it by the door, and slowly, tenderly, begins to mop up the blood. Sam closes his eyes. Dean's touch is like fire to him, but he can't bear to say anything, or even move, in case he ruins the moment, and Dean hates him again.

"Sam," Dean's voice is firm now. "Sammy, look at me."

Sam slowly raises his eyes to meet his brother's, and is overwhelmed by the love and protectiveness he sees there.
"We will work this out, Sammy. It's just... you kinda gave me a fright in there, man. Come here."

And even though Winchesters aren't given to displays of affection, Sam leans on his big brother and cries. Mostly, he's scared. Scared of his father finding out about the incident in the bathroom, or the incident with the knife. Scared that Dean won't feel the same as he does... and scared that he will. But there's a small part of him that realises he only feels truly complete when he's in Dean's arms.

Sam has always been the smartest Winchester... but he chooses to forget that for a moment, and simply be a fourteen year old boy in love.