They didn't dare risk anything in the Slytherin dorms, but the Gryffindor dorms were safe enough, even if they were discovered, and currently empty, apart from himself and Sirius.
He knelt over Sirius, tying each of his hands to the headboard, a Slytherin tie for his right, and a Gryffindor one for his left. He reinforced them with magic so that only he could release them. He stroked Sirius' cheek, and then tugged his hair. Sirius' eyes fluttered shut and his mouth fell open. Severus leaned back, tracing a finger across his bottom lip, along the line of his jaw, down his neck and Sirius' bare chest, across his abdomen, stopping just short of the tented boxers. He admired his handiwork. Sirius was flushed, and hard already, biceps tense as he pulled against the ties, head thrown back. He looked good enough to eat, and utterly fuckable. He ran his hands up Sirius' thighs, scratching slightly as he did, stopping just short of his cock. Sirius whined.
He repeated the movement with his mouth, kissing and licking and biting, grazing his teeth on Sirius' hip bones, hands holding Sirius down as he tried to thrust into it. He panted over the cloth covered cock, and then pulled away.
"Oh fuck come on." Sirius muttered. Severus smirked and moved further up his body, meeting Sirius for a kiss. Sirius submitted beautiful, head tilted slightly, and Severus lavished him with kisses until they were both short of breath, his mouth sweet and soft. He tugged Sirius' hair sharply, revealing his throat, securing him with a tight grip. Sirius groaned, and he sucked and bit at his pulse point as Sirius whimpered beneath him. Eventually he drew away, releasing his hair, and Sirius's head flopped forward, pupils blown.
"Oh please." He murmured. Severus caressed one arm.
"Please what?" He asked. Sirius glared at him only to sigh as he scraped his fingers across his abdomen.
"Please touch me." He asked. Severus ran a hand across his chest, then pinched and pulled on one nipple. Sirius arched into it with a groan, tugging against his bonds.
"But I am touching you." He said cruelly, repeating the action with the other nipple just to hear Sirius gasp. Sirius thrust into nothing.
"Oh please, please touch my cock, please." With a smirk Severus traced his hands down to Sirius' cock, and freed it from its cotton confines. He stroked it lightly, then leant down and sucked it down. Sirius growled as he placed both hands on his hips to stop him from thrusting, and moved up and down over his length. He licked and sucked and Sirius mumbled words of encouragement and thanks. Just as he approached orgasm, and Severus was well experienced with Sirius' orgasms, he pulled away. Sirius groaned, hands fisting.
"Oh god no, please just a little bit more." Severus smirked, and kissed him to shut him up. He pulled back to inspect Sirius, who gazed up at him with pleading eyes that weren't quite desperate enough. He fisted his own cock, stroking slowly, letting Sirius settle. After a few minutes he released himself, and kissed his way back down to Sirius' cock.
"Yes." Sirius hissed as he closed his mouth over it once more. He worshipped it, kissing and licking, using his spare hand to stroke the parts he couldn't reach. Sirius whimpered and tried to thrust against him as he teased him, bringing him slowly toward completion once more. As he neared it, Sirius' panted and tensed, and Severus withdrew. Sirius sobbed.
"Not quite yet." He declared.
"No, please, Sev, please." Sirius begged. Severus moved up his body and straddled his chest.
"Shush." He said, caressing Sirius' cheek, and pushing a thumb past his lips. Sirius sucked on it. He pulled it away, wiping the saliva on Sirius' face, and replaced it with his cock. He placed one hand in Sirius' hair, gripping tightly and eliciting a garbled whimper and thrust, directing Sirius' mouth as he pleased. Sirius took it prettily, sucking and licking what he could as Severus fucked his mouth.
"Such a perfect little slut." Severus whispered, tugging on his hair. Sirius moaned on his cock, gazing up at him with lustful eyes. He came hissing Sirius' name, Sirius swallowing around his head.
"Perfect. So perfect." He said, and Sirius smiled shyly. Severus moved back, sitting on his haunches, lax with satisfaction.
"I suppose you want to come now?" Sirius' cock was still as hard as it had been before. Sirius chuckled.
"Please." He rasped. Severus stroked it, taking his time, and Sirius watched with hooded eyes. He settled between Sirius' legs and summoned a jar of lubricant they'd experimented with before. He cast a quick cleaning spell and coated one finger with lubricant. He circled Sirius' hole with the tip of his finger, brushing over it as Sirius whinged under his touch. Fuck he was so responsive. He slid the finger in, and crooked it, taking a few times to find his prostate. He knew he had when Sirius arched his back and cried out. He stroked it, Sirius pushing back against him, writhing on the bed. He was fucking gorgeous. His cock twitched, and he debating drawing it out for another round, but decided against it.
"Please, please, please" Sirius begged.
"Please touch me, oh please, please let me come." Severus inserted another lubricated finger, using both to massage Sirius' prostrate. Sirius whined at the intrusion, wriggling and begging.
"I think you could come on my fingers. Would you like that? Coming untouched, just from the feel of my fingers inside you. So needy, so beautiful." He whispered. Sirius' pupils were blown wide and he shuddered at the words.
"Oh please." Sirius sobbed. Severus took pity on him, and swallowed Sirius' cock. After a few bobs and the continued unrelenting stroking of his fingers Sirius tensed, and convulsed, coming with a groan. He stroked him through it, inside and out, as Sirius panted, until he tried to pull away, sore with over stimulation. Severus stroked him once more, just to hear him gasp, then withdrew his fingers, wiping them on the sheets.
He released Sirius' wrists, checking he was undamaged and massaging them to get the circulation flowing. Sirius sighed, eyes closed, completely malleable in his arms. He cleaned them both, and then lay himself next to Sirius, propping one arm under Sirius' neck so his head was leaning against his chest. He stroked Sirius' hair, receiving a hum of pleasure for his trouble. Severus closed his eyes. He'd stay for just a moment.
He was rudely awakened by a loud cry.
"Sirius! Lily kissed me!" James Potter wrenched the drapes around Sirius' bed open, then gaped at them. Severus glared up at him, then summoned a sheet to cover the both of them with.
"Oh god. My eyes." Potter howled.
"What?" Lupin asked as he entered the room. He caught sight of Sirius and Severus.
"Oh wow."
"What?" Pettigrew asked, pushing past Lupin. He stared.
"I'm going to have to obliviate myself." Potter bemoaned.
"Do you mind?" Severus asked and Pettigrew finally looked away. Lupin coughed awkwardly, and Sirius, finally, woke.
"Was going on?" He grumbled. He opened one eye.
"Fuck off you wankers." He muttered. Severus snorted. Sirius turned over and buried his face in Severus' chest.
"Make em go away." He mumbled. The sheet almost slipped off, but Severus rescued it. Potter still got another eyeful.
"Why?" Potter cried, hands covering his face.
"Why didn't you cover yourself up before falling asleep?" Sirius, evidentially coming to the realisation that his friends weren't just going to leave, rolled over.
"I think I passed out, actually." Sirius said, with a guilty glance at Severus. He nodded.
"How?" Potter hissed. Sirius opened his mouth to speak.
"NO! Don't tell me." Sirius shrugged.
"You asked mate." They both sat up, and Severus wrapped a possessive arm around Sirius' waist, pulling him closer. He didn't like the way Pettigrew stared at them. Sirius tilted his head, resting it on his shoulder.
"Is Potter always such a drama queen?" He whispered. Sirius snorted.
"You totally ruined my news." Potter whinged.
"Go on then. Tell us." He said. Potter sat on the edge of the bed, then jumped up again, and sat on his own.
"Sirius would've been hard pressed to make a mess that far down." He remarked. Potter flushed and Sirius elbowed him.
"Shut up. Come on Prongs, what's up?" Potter's face lit up.
"I kissed Lily!" Sirius applauded.
"Well done. It only took seven years."
"Oh fuck you."
"Nah, I got Sev for that." Potter groaned.
"Why don't we go down to the common room, and leave them to get dressed?" Lupin suggested, and for once Severus was grateful to the werewolf.
"You're a genius Moony." Potter exclaimed. Lupin rolled his eyes, and hassled his friends out the door. Severus sighed, and fell back into the bed, bringing Sirius with him.
"Worth it?" He asked. Sirius snuck a hand around his waist.
"So worth it." Sirius mumbled.