Attention

You have to be careful about what you say. If you have and x that was bad to you they will use whatever you say against you. It is like they have nothing else to live for.
If you have and x that won't leave you alone you have real trouble. If you have children with them it is even worse. They never got over you.
So they are like little children. They want any attention they can get. They will use your children to get back at you. They don't care how it is hurting your children. As long as they have your attention. They only think about themselves and this can be fatal.
You really have to be careful about what you say or do around them. They are still in love with you so they are going over every word you say. They will cause fights with you as long as they have your attention.