There are so many ways Not to answer nosy questions. My favorite is just to smile. But then I have had to pull out a favorite from "Dear Abby" (remember her?!) from time to time. To a rude question she said it was appropriate to respond,"I can't believe you just said(or)asked that?!" And then continue not to answer. Or the other one, "Did you know you just said that out loud?", and not answer. That's if you're being pushed to answer a NOYBusiness question.
Have a great day...