Being a smoker and of a particularly aggravating persuasion, Severus doesn't so much as blink at the acrid cloud. (Which may actually look sillier than pulling away, who knows.) He does tilt his head, sticky black hair moving further out of the way of strangely bright black eyes.

"What would I be frightened of, Mrs Lestrange?" --Something he only ever called her to wind her up, honestly, and this is probably edging towards foolish on top of being a wildly inappropriate way for a teacher to interact with a student. (But if anyone thinks Bellatrix Black is an ordinary student, they need their head examined.) He shouldn't be playing this or any game with her, but something about seeing her - and seeing her like this - inspires an uncomfortable twinge somewhere enclosed in his ribcage. What does she look like now, in Azkaban?

Passive-aggressively picking a fight alleviates his guilt.

(Somehow.)

"Professor Severus Snape."