Hi JA customer and thanks for writing.
I am sorry to read your post and that you are in such a difficult situation. Your situation, however, is not at all uncommon.
Dating/becoming involved with people during a difficult divorce can be terrifically painful. For one thing, most relationships started during this period, do not last. I refer to them as the "transition" relationship and every one reads exactly like what you have posted here.
I think it is wonderful that you have been there for him during such a painful time, but at the same time I wonder how much you can expect from him now or in the future? These relationships rarely stand the test of time because they start out in such an unbalanced way (he was vulnerable and you were strong). As time goes on and he begins to heal this loss (and even if his wife cheated on him numerous times the failure of the marriage is a grave loss) the dynamics of your relationship will change. Only then will you know if he is in it for the long haul with you (no matter what he says now) and what your options can be. Seven months is a very young relationship under the best of circumstances and in this situation, where you have begun, under very bad circumstances it is too early to know what to expect.
As for how to handle his current behaviors? Let him do what he needs to do when he talks to his wife. If he needs to not hang up the phone and listen to her nonsense, leave him be to do that. If he becomes upset and aggravated when she manipulates his children, leave him be. Right now he is under tremendous pressures and the last thing he needs from you is more pressure.
I think you are wonderful to stand by him and I know you are trying hard to help him and help him to make choices to spare him more harm but the fact of the matter is that you may inadvertently be doing more harm to him and your relationship by not stepping back and letting him sort things out by himself.
Use care with yourself. As I have said before, relationships with people who are divorcing are risky at best, XXXXX XXXXX have been more than generous with your friend, but do not forget to take care of you while you are nurturing him. Make sure you are taking care of yourself.
Warm wishes to you.