I've met women like this, and the whole "dating married men" thing is not uncommon where we live.  It's like a badge of pride for these girls.  My husband gets hit on nonstop by these women, and the women see nothing wrong with what they are doing.  He doesn't like it, and neither do I.  Apparently, once a man is settled...it makes them more desirable towards loser women.  We've been dealing with this for over 15 years, and have noticed that every kid we had (we have 4) made them that much desirable.  It's pretty disgusting that they are that fucking desperate, and they take almost pride in trying to destroy relationships.