He had grand plans for his new life and they did not include any of the realities he has come to see. They usually don't and most of us have witnessed this.
It is nice when they can be civil for moments, but it should not be confused with them becoming "normal". They can't handle normal. Normal is life outside the tunnel. It scared them. They ran from it and are alien to it. Some of them will simply choose a life in the tunnel as they feel they have control there.
Being civil may just be a learned behavior from him that you can be thankful for, or occasionally encourage. It would make dealing with him more tolerable. But ... do not give up control of your boundaries. Do not let him think his moments of civility eliminate the need for boundaries. Instead, civility should simply be an expected behavior that is maintained around the kids and enjoyed by both of you. But he probably will act out every time he is reminded of what is in your control now, and not his.
As history repeats itself OW will see his life in the tunnel for what it is and loose interest in it. Sooner or later he will be challenged to live outside the tunnel, and he will rebel. Not your problem. People living in the tunnel are no prize to anyone.
