WHG, I just wanted to say you are doing a great job as a Dad for your S and for your SS & SD for that matter. You're stepping up to the plate for your kids. Your S is watching you and will always remember the way you handled things. Also, as far as I know, my W moved out first on the premise of "finding herself" (TBH I wasn't totally buying it) and then started dating. So I understand what you're saying about OM. In some ways, it doesn't seem like he's OM because of the sequence of events, I think.
