Wait...so you stayed with her for TWO years, after she cheated on you THREE times? Somehow...I get the feeling she isn't the only insecure one.
I take my first post back..I have no pity for those that make their own bed, then complain because they have to lay in it. The only person that can improve your life is YOU...dump the cheating broad.
P.S....I try not to make broad statements when I only hear one side of the story, but there is NO excuse for infidelity.
