He stiffened visibly when he affirmed that he was a Death Eater, jaw tight and wand lifting up to point squarely at his chest. Sirius was saying that Harry was close with a Death Eater? And he said it so.. calmly. He said it like it wasn't a big deal. But it was. It might not have been to Sirius' Harry, but Sirius was in for a big surprise. Harry wasn't anything like the Harry Prewett knew. The one he'd practically raised. The one whose temper didn't flare up on a moment's notice, the one who didn't over-react to simple situations. The one who didn't jump to conclusions.
"Roll up your sleeve." Demanded, green eyes narrowing behind his glasses. "Stand up, and don't touch your wand." Because he still didn't have an inkling that Sirius could do wandless magic. He had a wand, after all. He had no reason to believe that he could. Yet.