My dad is a professor in an area related to (but not the same as) mine. I briefly mentioned this fact while out for dinner interviewing for a faculty position. The professor sitting next to me (a woman!) then asked me if my dad was my advisor. It was obvious she was really asking if my dad did my thesis research for me. I was so dumbfounded and offended that I just stuttered out that there was no way my dad could be my advisor since we were at different universities.
It’s possible this was an age/seniority thing rather than a gender thing, but regardless it left me with a very poor impression.