I have no idea what I would say. I think he is a sad existence of a human being. He was my wife's boss when he told her that "loved her". He is telling her that our children are not benefiting by living in a "loveless marriage". He has given her information on how to deal with the children in a divorce. The whole time telling her that he will just back away if she thinks that we have a chance. And that is just the tip of the iceburg.
This guy is a threat to your marriage don't stand by and watch. You confront your wife and tell her that you will not share her with another man. She will stop contact with him and there will be transparency. If she says that she talks to him because of work then help her find a new job. This is a very serious issue and inaction is not the answer. Handle it.
M22,H45,W45 S21/18D12 Retain faith that you will prevail in the end, regardless of the difficulties and at the same time confront the most brutal facts of your current reality, whatever they might be.