I just had to say this one little thing
 

all women who are single mothers with children are not that way because of a married man.

~Now let me clear throat~ (sing the song) okay stop!
this is a really good topic, I figure it's low self esteem on both the man, and the other woman.
I mean who wants someone elses left overs ???
Maybe because I pride myself in being the one and only, and if I'm not, then to hell with you.
I agree with spinxpoet, if THEY could follow those two rules, we wouldn't have drama.