Sirius could tell that his friends were fed up with him and he did not care. Potions, double Arithmancy, double Defence Against the Dark Arts, and all their professors incessantly reminding them that practice NEWTs were coming up soon. Sirius had had enough. To make matters worse, he had spent half the day with a raging hard-on, and no time to do anything about it.

He had been planning to take a shower with Remus that morning, but Peter had dawdled in the bathroom until they only had ten minutes to get to breakfast. Sirius spent the day shooting a string of Pinching hexes at his short roommate, and mouthing off at everyone.

When Peter jumped for the fifth time during supper, spilling his pumpkin juice all over the table, James, who had been about to achieve actual conversation with Evans, shot Sirius an annoyed look.

"I dunno what crawled up your arse today, mate, but would you go extract it and stop making a nuisance of yourself?"

"Sorry," sneered Sirius. "Am I distracting you? It's not me who's keeping you from getting into Evans' knickers, mate. She's never going to touch your parts. Keep barking up that tree, and you'll die old and saggy and alone, like Pete."

The red-haired girl narrowed her eyes at him and shifted farther down the bench. James, who normally had no temper to speak of, looked as if he was about to launch himself across the table and throttle Sirius.

"You want to watch your mouth, mate," he bristled, "unless you enjoy spewing slugs."

Sirius was just about to snark back, when Remus, who thus far had bourne Sirius's moodiness in silence, leaned over and murmured in his ear, cool as anything, "If you don't stop being such a bad dog and apologise right this minute, I am not going to fuck your brains out later."

Sirius's mouth snapped shut and his eyes lost focus for a moment as his cock gave a painful throb. He dropped his gaze to his plate. "Sorry," he mumbled.

Peter and James glanced at Remus, eyebrows raised. The young werewolf gave them a bland smile and turned back to his supper.

The rest of the meal passed in silence, but Sirius kept casting furtive looks at Remus from beneath his lashes. Remus ignored him, but every now and then, he would delicately lick or suck some stray dollop of food from his fingers in a way that made Sirius almost whimper with longing.

In their dormitory after supper, Sirius tried to focus on his school work, but his mind was in complete disarray. After an hour or so, Remus sat up, putting his own books away.

"James, Pete," he said lightly, "could you give us the room for a minute? I want a word with Sirius about his behaviour today."

Their roommates glanced at Sirius, then at one another, shrugged, and departed for the common room without a word. When the door closed behind them, Remus considered Sirius for a long moment. Sirius returned the look with just a touch of defiance. His heart was pounding. Remus could be very creative when it came to punishments.

Finally, he seemed to reach a decision. "Come here. Bring your collar."

Sirius hesitated only a moment before reaching into the nightstand drawer for the black leather collar that he sometimes wore as Padfoot when they were in public. He slid off the bed and moved towards Remus, mouth dry, palms sweating. There was a dangerous look in his boyfriend's eyes.

"That's close enough," he said when Sirius reached the middle of the room.

Sirius halted. "What do you -?"

"Shut up."

His obedience to Remus's command was almost instinctive. His mouth snapped shut, and he swallowed hard.

Remus stood up, taking a step closer. His face was completely unreadable. "You are being punished, Mr Black. You will not speak or make a sound unless I give you permission to do so. Am I understood?"

Sirius nodded.

"Undress and put on the collar."

Slowly, Sirius shrugged out of his robes and shed the rest of his clothing onto the floor at Remus's feet. When at last he stood before him, naked and hard, Remus nodded in approval.

"Good. Now I'm going out on my rounds."

Sirius's mouth dropped open, but Remus gave him a warning look and strode over to James's trunk, rummaging for a moment before pulling out the Invisibility Cloak. He retrieved a handkerchief from among his own things, and stepped behind Sirius.

"You are going to follow me like a good puppy. Hold still."

Sirius obeyed, hardly breathing, as Remus bound his eyes with the folded fabric. Leather and steel constricted around his throat as Remus tugged the collar one notch tighter. Then the light, soft folds of the cloak settled over him, and Remus took his hand, placing it firmly on his shoulder.

"Not a sound," he reminded Sirius, turning towards the door.

The way down to the common room and out of Gryffindor tower was easy. Sirius did not need to see. He had walked it so many times that he could do it in his sleep. As they passed through the common room, Sirius felt the warmth of the fire on his skin, and heard the voices of his Housemates all around him, including his best friend. He felt exposed, terrified, elated, naked without his clothes and wand. The cloak swished and whispered deliciously against his skin, softer than silk, and he knew that James would murder them both if he ever found out half the uses to which his friends put his most treasured possession.

At the portrait hole, Remus paused so Sirius could jump down. It was cold in the corridor, and he shivered, though the cloak offered some protection. They walked the halls in silence. Every now and then, Remus would greet a ghost or a fellow prefect, or would mutter something like "stairs" over his shoulder. Sirius stepped carefully behind him, stumbling occasionally against Remus's heels. After a few turns, he no longer had any idea where they were.

They walked for what felt like miles. Finally Remus halted. There was a sudden whoosh of cold air, then Remus was under the cloak with him, radiating heat.

"You've been a very bad dog today, Mr Black. I think you know that." Remus's voice was low, his lips almost touching Sirius's ear.

Sirius swallowed hard, feeling the tightness of the collar at his throat.

"Bad dogs need to be punished, don't they?"

He nodded.

Remus's fingers tugged lightly at the collar, before ghosting down his front, making a detour around his aching cock. A small sound escaped Sirius's throat, and the touch vanished.

"I believe I ordered total silence, Mr Black." Remus's voice was cool and even.

Sirius bit his lip, bowing his head in remorse.

"Silence is even more important from here onwards," said Remus. "You will not make a sound, no matter what happens."

Sirius could only nod again.

"Good. If you disobey me, Mr Black, I won't touch you for a week. Nor will you touch yourself."

The thought made Sirius feel dizzy. He was painfully hard already. He needed to come soon, preferably with Remus's hands on him. He could feel Remus's eyes blazing over his skin, assessing his need, and wondered how the other boy could sound so cool and collected.

Remus's hand closed firmly around Sirius's upper arm, guiding him a little farther, through another doorway.

"Now, we wait," said Remus, letting go.

Despite the limited space under the cloak, Remus's body did not touch his anywhere, which Sirius felt was punishment enough for his sins. But Remus's word was law, so Sirius waited in silence for whatever came next.

A door opened and closed somewhere nearby. Voices entered the room. Sirius's heart skipped a beat. McGonagall. And Sprout. Within moments, several more of his professors had joined them, exchanging greetings and pleasantries. Remus stood still and silent beside him, but Sirius was trembling now, caught between fear of discovery and desperate desire for the commanding boy at his shoulder. Chairs scraped against the stone floor, and there was the sound of liquid being poured.

"Thank you all for coming," said Dumbledore's voice. "I know staff meetings are no one's favourite way to spend an evening, so let us make this one brief."

With a light push, Remus urged him forwards, and Sirius put out his hands to catch himself against sturdy upholstery. A hand on his back pressed him down, while another on his hip drew him back. A scuffed trainer nudged his feet apart. With a tug, the blindfold came away from his eyes.

Sirius blinked. They were in the staff room, of course. He had worked out that much. A dozen professors were arrayed around a long table not ten feet away, enjoying tea, sherry, and biscuits, completely unaware of Sirius, bent over the back of the old sofa, legs spread, open and exposed to the prefect behind him.

Remus laid a hand on his arse, bending down to whisper in his ear. "Do you want this? Do you want me to fuck you here?"

Sirius could manage no more than a jerky nod.

He felt Remus rummage through his pockets for the small phial of lubricating potion he sometimes carried, and then slippery fingers were sliding into Sirius, probing and twisting in a familiar and agonisingly delightful way. Sirius swallowed a gasp. Remus tugged open his trousers, and then he was pushing into Sirius, quick and rough. Sirius bit down on his lip hard enough to draw blood as Remus tested his promise of silent obedience to the limit.

He wanted to moan, to cry out, to beg Remus to touch his prick, but he did not. He would not. Not without Remus's permission. His eyes watered. The staff room blurred and went out of focus, and all he could feel was the burning hot slide and thrust of Remus's cock inside him, Remus's fingers digging into his hips. His own erection rubbed against the back of the sofa, the light, smooth fabric of the Invisibility Cloak providing an easy glide. James would definitely kill him if he came on the cloak, but when Remus shifted the angle of his hips and hit that spot, there was nothing Sirius could do but bite down on his broken lip as orgasm shuddered through him.

It was a good thing that Remus had mastered the art of silent Cleaning charms, he thought fuzzily as his knees gave way. Remus's hand was around his arm, supporting him, guiding him down to the floor. They sat with their backs to the sofa, Remus's arms around him, pulling him close. The professors' voices faded to insignificant murmurs on the other side of the room. Warm, slightly sticky fingers raised Sirius's chin, and brown eyes searched his face as a thumb brushed lightly across his bitten and bloodied lip.

"Good dog," Remus whispered affectionately, and kissed him.

Sirius relaxed into Remus's arms with a sigh of contentment. "That was brilliant."

Remus gave a breathy chuckle. "It sort of was, wasn't it?"

"Could we - maybe do it again sometime?" Sirius asked shyly.

Remus's eyebrows rose and he grinned. "Well - as often as you misbehave, Padfoot, I could see having to - ah - 'take steps' with you again at some point." His expression changed to one of mock sternness. "But don't you go abusing it. I can think up punishments you won't like."

"See, Moony? This is why they made you a prefect," Sirius grinned.

Another near-silent laugh escaped Remus's lips. "So I could debauch you in the staff room? Somehow I don't think that's what McGonagall had in mind when she talked about me 'controlling' my friends."

"You've got authority, Moony," Sirius told him. "People listen to you."

Remus gave him an indulgent smile. "Well, it's a good thing you'll listen to someone, Padfoot. Are you ready to show me you can be good for a while?"

"Anything my Moony wishes," said Sirius with an impish grin, but the kiss he gave Remus was soft and tender.

Chair legs scraped against the stone floor once more, and the staff room began to empty. Under the Invisibility Cloak, the two boys peered over the back of the sofa, waiting for the coast to clear. Dumbledore was the last to depart. He hummed to himself as he tapped together a stack of parchment and stoppered the decanter of sherry. At the door, the headmaster paused.

"Good night, lads," he said, eyes scanning across the top of the sofa. There was a twinkle in his bright blue eyes. "Do try not to startle the house-elves when they come to clear up."

The door closed with a soft thump. Sirius and Remus stared at one another, openmouthed.

Sirius was the first to break. He gave a bark of laughter and collapsed, wheezing and snorting, over the back of the sofa. "Godric's balls!" he gasped. "He knew. The whole time we were - Oh, Merlin!"

Remus buried his face in his hands, but his shoulders shook with suppressed mirth. "I am never going to be able to look him in the eye again. How did he know?"

Sirius shook his head. "No idea, mate. He's Dumbledore, I guess."

Overheated by laughter, Sirius threw off the cloak and stretched, as Remus, too, emerged, red-faced and tousle-haired, his trousers still undone. Ignoring the interested looks and murmurs from the portraits of past professors on the walls, Sirius walked naked to the meeting table, and hopped up to perch on the edge of it, swinging his feet and grinning at his boyfriend.

"Shouldn't we be getting back, Padfoot?" Remus said regretfully.

"That keen to explain to Prongs why I'm not wearing anything but his cloak and my collar?" Sirius raised his eyebrows.

Remus grimaced. "You have a better idea?"

"I was thinking we might wait and go back after they've gone to bed." Sirius leaned back on his elbows, grin widening, legs spread in invitation. "In the meantime, you could take off your clothes and come over here, and I'll show you just how good I can be."

In the end, they did startle the house-elves.