I was in the middle of writing a Soul Eater fic when the song "Sooner Or Later" by Mat Kearney started playing and I was hit with a lightning bolt of inspiration for this. To be honest, I love it.
There's a strange sort of bitterness to wanting someone you wish you didn't. Someone you shouldn't. Someone you can't.
Because you want to smile when he does. You want to let your mind trace over those fleeting moments of physical contact. You want to be able to pull out those few memories where he was kind to you and hang them out in the sun to blow in the breeze. But you can't.
You can't, because with each thought, there is always the kick of wrongness, a pain that doesn't belong in this emotion that you sometimes think is love. Because he is your stepbrother. And you never wanted this to happen. You had plans, you KNEW how your life was going to go, and it didn't involve him anymore than it had to.
But somewhere along the way, the curve of his back drew your eyes. You found your gaze lingering on the strip of skin above his boxers that shows when his shirt rides up. And when you fight, you never know whether to look at his eyes—they always get darker when he is snarling at you, and you like to pretend that maybe it's because of a different feeling than anger—or at his mouth—watching the shape of his lips forming around your name.
You want. You want so badly. It dances around in your head; maybe if you could just grab the front of his shirt and drag him across the canyons between you, smash your mouth to his for one kiss, one moment to hold forever, then you could drive his presence out of your head, your chest, your bloodstream. Sometimes you can feel his lips against yours so vividly, when you lie in your bed at night, that you could swear that he is leaning over you, right there, real, for once. But he never is, and in a way, that's how it should be.
Because you want, but you don't want to want. There are ties between you already—one of them labelled with the hated word: "family"—that eliminate any possibility of new ties. So it doesn't matter, not your speculation about whether he feels the same, about whether his hands sometimes linger on your shoulders and your hip out of a desire to touch you longer rather than simple absent-mindedness. Because you can't, so you won't, and you don't want to. These memories, these thoughts, these ideas, can never hang in the sun: they are the dirty underwear, never to be displayed to the public, never to be acknowledged.
And sooner or later, you tell yourself, you will believe that. And the bitterness will fade.