Mel, I found out my first H was seeing OW from my own mother who heard it from my kids who were 6 & 9 at the time. When I confronted him, he didn't deny it - I told him it was inappropriate for the kids to know - and it needed to stop until we lived in sep places. We were sep at the time but living under the same roof. I talked to the kids who were confused and surprisingly not wanting to be angry with their father. I did not try to give any excuses for his behavior nor to say anything negative about him. I would talk to your son to see what he knows and then what he understands - remember kids don't understand things the way we do. I would offer him the oppt'y to live with me if he wanted but wouldn't force it. My kids were afraid of their father but wanted visitation anyway because he was their father. As my kids got older and wiser they told me that staying out of the middle between parents who are sep/div allows them to have a life. In any case, slowing down and thinking things through i.e. what are the consequences of each action I take and which one can I live with. One thing i noticed in reading your posts about this R is that you both have been reacting instead of thinking when it comes to facing each other. hope this helps.