Sirius chased the shiver, but slower than perhaps anticipated considering his nature, with a finger running the entire length up before more fingers dug in to scratch their way down. It was slow but rough, hard, and demanding. That back was becoming his, marked with scratches that showed he had been there. His fingers began running across them, feeling them even as they moved, already breaking the skin in a few places.
His mouth fell back, surprised at the sudden movement with little notice. But his face tilted down, taking in the chest before him. Sirius had seen it before, of course, as sharing a room for six years had a way of making modesty pointless. But he hadn't ever checked Remus out like this. Doing that without someone's consent was...wrong. The scars were hot and filled Sirius with the crazy desire to lick and bite his way across each and every one of them. But before he could, Remus was kissing him again, and those hands were on his face, so he couldn't really complain. One of his hands worked its way around and began scratching across Remus's chest, tracing the scars as he did.