A/N: This was written a while ago. Bits of it make me laugh now. Ah well, still fun!

First Time

Where the hell was he? Sirius shivered in his pyjamas, carefully pushing open the recently locked door of the library. What the hell had James been thinking, letting Moony borrow the cloak, how were they meant to get the map finished at this rate?

Quietly he tiptoed past the bookshelves, peering ahead into the darkness. James' cloak was the famous Cloak of Marauder Invisibility, it was an outrage to use it for sneaky study lessons. And it wasn't as if Moony needed anymore time to study, he seemed to spend his whole life buried in some book or other.

He had never been out in the castle without the cloak before. It would have made him scared, were it not for the fact that Sirius Black had learned long ago how to turn fear into anger.

He was shaking by the time he saw it (with cold, yeah, the castle's cold at night), a small lantern shedding a dim circle of light onto a high stack of books. A worried looking boy sitting in the centre, chewing on a quill pen, staring down at the papers in front of him.

"Moony!" It's hard to sound angry when you're whispering, but Sirius gave it a try.

Remus gave a small jump and looked up, "Wh- oh, Sirius."

The eyes lowered, the head bent back over the work.

Sirius blinked. Then, eyes full of mischief, he crept up behind Remus and grabbed his arm, twisting it behind his back and making the startled boy drop the quill.

"Hey!"

"Shhh Remus. Someone might hear us."

"Aarg, Sirius that hurts."

"Fine." Sirius let go and moodily kicked a stack of books. "My little brother doesn't even yell that much."

Remus sighed, rubbing his shoulder. "What do you want?"

Sirius looked crouched down next to Remus's thin shivering body and tried not to let his mind run away with possible answers, "Er, just the cloak."

Two large soulful eyes looked up at him, "I need the cloak to get back."

Sirius swallowed, trying to breath normally. Relax Sirius, you don't feel anything for him. He's your mate, and you're... you're tired. Yeah.

"C'mon Remus, you've worked enough today." Sirius made a grab for the cloak at the same time as Remus, showing masterful foresight, grabbed it at bundled it up in his arms.

"I need this time Sirius, I've almost finished catching up on the work I missed last full-moon."

Sirius narrowed his eyes, trying to ignore the fact that his heart was going mad in his chest, "Give me the cloak."

Would he cave-in? And somehow there was a part of Sirius that desperately hoped he wouldn't. For Remus to give in now, to hand over the cloak with that horrible sad little droop of his shoulders, would be the worst way the night could end.

How did he want this to end?

Sirius realised his hands were shaking.

And suddenly he hated Remus for doing this, hated him for making his body want to do things that Sirius Black could never do, for putting him in this impossible situation.

He shuddered slightly, remembering the things James had said about Snivellus and Malfoy behind their backs (and sometimes to Snivellus's face) the words he'd said, that sounded so... dirty.

Remus shook his head, fingers tightening over the silky grey material. With a growl that could have been either lust or relief, Sirius leapt across the intervening distance, shoving Remus down roughly, grabbing at the cloak.

And then Sirius was tugging Remus's shirt off, and somehow his pyjama bottoms were around his knees. Remus was gasping and panting and Sirius swore at him before pulling him upright and pushing him against a bookshelf.

"Damn you Remus, I'm not a bloody pouf!"

He pushed a finger into Remus, who moaned and pushed back onto him.

This wasn't like girls, this wasn't like girls at all. For one thing, he was feeling things, there wasn't the horrible embarrassing terror of his hardness giving out at the wrong moment. He didn't have to be gentle with Remus either.

He shoved another finger in, grinding it roughly. Beneath him Remus squirmed. Sirius's breath came in ragged gasps, as he pushed Remus into the books.

He pulled his fingers out, feeling slightly disgusted with himself. His body, however, knew what it wanted and surged forward eagerly.

Remus cried out as Sirius thrust deep inside him. A cry that started out as pain and morphed into choking pleasure as Sirius began to pound against him. The small part of Remus that wasn't baying for blood was frozen in terror at the thought they might be discovered. They'd cast no Silencing Charm and the lamp was still bathing the shelves in a soft yellow glow.

His hands grasped the bookshelves in front of him, he was gasping and writhing and then felt Sirius shudder against him before lying still. Slowly he opened his eyes and found himself face to face with Numerology and Grammatica.

"That was... interesting," he murmured.

Sirius shuddered again and withdrew, before collapsing miserably onto the floor. "I'm not a pouf Remus."

"Ah." Remus didn't know what to say. He thought of the long hours he'd spent in the History of Magic class, staring dreamily at the back of Sirius's head and allowing his thoughts to wander through all sorts of dark forbidden alleyways. "Um, me neither."

"We can't tell James."

They both thought for a moment of the strong, confident, clearly-straight Quidditch captain. "No."

There was silence for a bit. Remus shivered and Sirius put an arm around him.

"Just mates then?" Remus asked, uncertain of the dynamics of this.

Sirius made a muffled sort of noise and licked his earlobe. "Yeah," he muttered indistinctly.