Severus averted his eyes, glad for a kiss to keep Sirius from looking at him like that. As they came apart and pressed together again, evidence of their bonding dripping lightly across his arse and thighs, Severus nosed Sirius' cheek and curled his fingers gently around the other boy's ear. He didn't know why, but his thumb lightly rubbed the tip of it as one might do to a dog. He had no idea what Sirius Black could do, but the linking of magic inside of him did have some idea, hidden deep down.

Severus would never ask Sirius if they'd do this again. Or if they'd have to hate each other in the morning. His berry red lips poured lightly. His dark voice, so odd for one so small and pale, cracked when he spoke. "Don't. I didn't do you a favour."

It was a right if he had been used. He'd get over it. But he couldn't bear being thanked for it.