Severus looked thoughtfully between the two of them for a moment, not deigning to give Black a response as his mind made a few preparations for the task. He tightly closed off his own thoughts while he searched the room for any sort of chair. Spotting one in the far corner, he withdrew his wand and Accioed it over, catching it when it zoomed closer. Wordlessly, he sat beside the bed and leaned forward, fighting the urge to grimace at the breaking distance between himself and Black.
Low and serious, he kept his wand out just in case. "I'm sure I will despise this just as much as you, but your friend here has been so kind as to let me proceed." Dark eyes shot a tight look at Remus before returning to bore into Sirius.
"In order for this to work, you need to keep your eyes on me. No stupid comments and we can finish this up that much faster."