Parvati's eyes narrowed just a little. She was much more perceptive than some gave her credit for, and would call someone out on evasive speech without a thought. Being Draco's wife however, meant that more than often she had to bite her tongue to appear the submissive, pureblood wife that their society demanded her to be. In her own house however, toward her husband and people from her past (And Snape was included), she didn't feel the need to hide her intelligence or opinion.
"Yes, but by noting that, aren't you simply making sure I remember that you did once hold that power? Regardless, I need something acceptable to call you - I feel as if your given name would be disrespectful of me. In my culture a respected family friend is often referred to as...well, uncle." Her face scrunched up, as if she wasn't sure whether to laugh or vomit at that possibility. "And then the only other choice is, in fact, Professor."