My husband and I have been married for 5-1/2 years.  He shares an 18 yo daughter with his ex.  His ex cheated on him several times then finally left him.  I came into the picture a few years after their divorce.  The second I came into the picture, she decided she wanted him back, even though she had a live-in boyfriend.  I'm not dumb enough to think she really wants him back.  Her only motive is to get at me.