Thomas the Rhymer, I agree with you (I think). The point I was trying to make above (and not very well, most likely) was that you can't really take offense at someone who means no harm. They're just socially STUPID.

No matter what whacky question I've ever been asked, I've never been rude to the person, for Pete's sake! There's no need. Even, "Have you ever had an abortion?" (which made my eyes bug out of my head) lol I just said nicely, with an amused expression, "I'm not going to answer that." If you let them know gently, that it's an inappropriate question, they back off and usually apologize. To me, that's a much better outcome than if I got all defensive and snapped at them with some nasty comment or sarcastic, rhetorical question. It would make them feel bad and that would make me feel bad.

It's not necessary to "get back" at them. Some people can't spell, some people can't do math (me) and some people have no intuitive "feel" for interpersonal relations. (shrug)