This is something that only both of them knew. According with Rabbi Schmuley's book "MJ's tapes", Michael dicho that Lisa followed him and begged him to come back to her after they broke up. They still met few years after the divorce. I've also read that they were very attracted physically and this was the thing that kept them together. They also used to fight very often. I believe her problem was that she wanted Michael only and only for her, maybe she was a bit possessive and this was not possible with Michael. She could not accepted nor fit in his world where children, charity was his #1 priority. When Michael dicho in an interview that he met women who were jealous on their own children and started compete with them (to have his attention), Lisa came in my mind first.
Well to me the truth is that Michael and Lisa really loved each other, but Michael felt broken hearted when Lisa broke her promise that after the marriage, they would have children,Michael wanted children so badly because he never had a normal childhood. He had a feeling that Lisa didnt much care about his life, but they still got in touch together after their divorce. The couple did get along, but they divorced because Lisa didnt want to raise a family with Michael. Michael had 2 children (Prince and Paris) which he raised with Debbie Rowe and another child (Blanket) which he raised with and unknown surrogate mother. Michael And Lisa still get along after the divorce, She dicho she was in a full flood of tears when Michael died..... i respect your pregunta anyway :)