Hi Loving. Did you find a way to talk to your son? I would welcome any feedback about how you have done it. I've read so much about the best way to do things, but it just doesn't seem like there are good answers.
We are still living together but someone is going to have to move out soon and I don't know whether to tell my son without checking with my husband, or to give our son time to process, or wait until the last minute.... My husband won't cooperate and we can't discuss it because he will just insult and belittle me, blaming it all on me. I want to respect the fact that my husband has been a good father to our son, even though he has been a horrible parter to me, and minimize the harm and instability for our son. So hard to know.
Hope things are going better for you. This is of course especially hard during the holidays.