Severus didn't need exclusivity for that reason. He just refused to sleep with someone sleeping with other people. It disgusted him to think of where Sirius's cock might have been. The boy wanted to put that very organ into him afterward? No. A thousand times no.

He clung to the front of Sirius's robes, fingers moving to the shirt beneath. "I won't say it," Severus promised. Compromise. It was all about compromise. "But no, you can't have sex whenever you want it. There are logistical reasons. And I'm not your whore."

He had an odd feeling that he was talking like a woman. He needed to rectify that.

"I want to try being the one to penetrate."