My ex-wife and I are like this. Why on earth?

I don't think you have understood each other yet. In other words, there are still contradictions and concerns. On the whole, there is still no trust between us. If both husband and wife don't trust each other and feel insecure, they dare not be with each other even if they think about the past. There may be other factors, such as the ideas given by your parents. If you really don't know what to do, you should talk to her. When you speak, you should know what you want in the end and what she thinks. You are making a decision after you know the answer!