Thank you! Curiously, when all this started up (nearly a year ago now) I said to my eldest son that I wondered if his cancer had come back. Actually I think the other explanation is that he misses us all very very much and has no idea what to do.
His anger is maybe at himself, and the situation he is in. Obviously huge pressure from OW2 to get married, but dare not give up on her and take the risk of trying to get his family back, even for friendship.
But apart from when it impinges on me, it isn't my problem