I ask them why are they asking me that. Or why they want to know. It makes them stutter and look like a complete idiot and they don’t know what to say because they know they were being rude by asking stuff that’s none of their business. Bring the topic back to them and they will leave you alone. Also there were a few people at work who’d make comments but they would make comments about everyone. I’d just laugh them off. Work is way different then when I started though and now all those people are gone.