The Grave Soul
You are not like the other boys. You've always known it, but now you have a secret even beyond the one your friends discovered in second year.
You try to hide it; you don't shower with them anymore, don't stick around while they change. Sirius walking half-dressed through the room is enough to send you fleeing to the Prefects' bathroom, where you spend a lot of time wanking.
When Snape corners you, you feel a thrill of something beneath the fear. When his lips brush your ear and he says, "I know what you are," you shiver, and not just because you're scared.
It doesn't take long for you to learn he's got one secret, but not the other. But since he is the same -- his lips on yours, his hands down your trousers -- you feel safe sneaking off together. None of your friends -- or his -- would let either of you walk away from this unscathed, but it is your secret, and it is good.
You see him almost every night for a month, but the day of the full moon you tell him you can't meet him that night. His face falls, and he says something nasty about Sirius and your loyalty to him.
You bite your lip, because you can't deny it. Sirius is an utter prick, and you've done nothing to stop him. Sometimes you're amazed that Snape will even speak to you, let alone touch you, but then you remember -- he's not going to be pulling Miranda Bassett or Philippa Cairns when you go to Hogsmeade. You only have each other, and the secret you share.
"I'll see you tomorrow," you say, finally. You want to tell him to come to the hospital wing, but you can't. You can't trust him with that last secret. Not yet.
The next morning, you wake in the Shack, Pomfrey hovering over you like a mother hen. You can taste the blood in your mouth and you retch repeatedly over the side of the bed before you rise.
You spend all day in the hospital wing, sleeping fitfully, wondering why no one came, wondering why the wolf was even more vicious than usual. You vaguely remember the scent of fear and blood, and you hope everyone else is okay. It's not like them not to visit, and you worry, even though Pomfrey tells you they're all right.
You stumble back to the dorm while everyone is at dinner, grabbing a clean set of clothes so you can have a long soak in the Prefects' bath.
Snape is waiting there -- it's your usual meeting place. You smile, lean in for a kiss.
"Don't ever touch me again, you filthy beast," he hisses, drawing his wand with a trembling hand.
He stalks away, robes swirling around him, and you lean against the wall. He's not the only one shaking.
You manage to keep from crying as you sink into the warm, bubble-filled water, but only just.
You promise yourself you will never share your secrets again.