My ex says that my children are my problem and laughs when they misbehave?

You know what the situation is. Now you have to do better for your children. If your son is stealing, there is a lesson you have forgot to teach. Maybe, you should forget about men for a little bit and get your life back on track. You can't depend on someone like this to help raise your children. A body next to you, is not worth their future. Geez.