That's a valid reason to ask some questions about the past. I may need to revise this a bit, because the point is not that you should NEVER bring up someone from the past. We all have a past, and our previous relationships contribute to who we are. But , as you said, if someone has a series of "crazy" exes or they can't speak nicely of any of the people they've ever dated, that should definitely be a red flag.

I guess more what my point was, was to say that there's a point where some brief discussions of exes needs to happen, but then it should be over and done. Exes shouldn't be getting brought up repeatedly - and former competition should NEVER be brought up, because you didn't choose the competition, you chose the one you're with.