Title: You Mean So Much
Characters: Sam (/Lucifer), Dean
Rating: R
Spoilers: Season 7
Warning: mentions of sex, less than brotherly fluff
Summary: Dean is blind. Too blind to see.
The thing is: Dean is blind. Too blind to see. Too blind to know that Sam has probably slept with more people than he will ever know. Is it Sam's fault that Dean believes his little brother doesn't do casual sex? No it isn't, but perhaps it has to do with the fact, Sam hates picking up girls in bars.
Fare more likely is it for Sam to fuck whatever runs across him, when the monster of the week is still bleeding on the floor. The rush of the hunt and the killing has always been a part of Sam's nature, but after Dean sold his soul the feelings intensified. The fear, the need for control and release nearly ripped him apart, when he hunted the Trickster in the six month that no one else remembers.
Sam still remembers the blood and the semen between the Trickster's legs, the ecstasy he always felt, when Ruby cornered him and when Castiel came to him, the angel's feelings bordering on endless sexual frustration. All theses meetings never happened in secret, not really. Drinking blood, yes. Fucking in the open behind some barracks? No.
Dean just never bothered to look beyond his own valued opinion.
But in this case Sam doesn't dare to challenge fate. Lucifer is different and Sam doesn't want to lose him to Dean's narrow-mindedness. Lucifer is too important to treat him like a fling he could shrug off with a 'not now, perhaps next week?' manner. When he wants Lucifer, he usually wants him right here and now. Sam's simply can't not want Lucifer, especially not when he is reminded how it was, when they were one. When they burned together and shared everything.
Since Dean will never leave and never understand, Sam insists that Lucifer warps reality. He isn't sure if it's just inside is head or if Lucifer just lets Dean live in a constant haze of booze these days. Probably a little bit of both, because there's never a hint, a clue or a sign that Sam spent the night entangling himself with Lucifer as much and as deep as he could.
Lucifer is his secret, Sam degrees with possessiveness. And he wants it to stay this way.