I don't mean to brag, but this has happened to me. I also wonder if they're attracted to prettiness which is equal to femininity, whether it be a man or woman. I can't figure it out, but I've had 3 guys with huge crushes on me, who later I leared are gay. I'm dieind to ask them then how they expected us to have a relationship. I was never romantically itnerested in any of them.
Likely the same thing as with my mother -- they were attracted to men attracted to you....