Severus sucked in a breath at that particular touch. It was a bit ticklish, a bit too light. It make his skin tingle. Watching Sirius through half mast lids filled him with all sorts of euphoria. Why? He had questions and now be needed answers.

Of course Severus did notice that Sirius seemed to be waiting for him, going only so far before drawing back again. Was the Gryffindor attack dog waiting for another order? Praise? He really had no idea how right he was to classify Sirius in the canine catagory in the first place.

"Undo your trousers."