I certainly know what you're saying about confrontation (we're probably worst than most because of our backgrounds!)but does anybody really like it?
I thought the response that the girls helped you with was perfect. Now that I feel I have all of this "experience" under my belt, I can tell you that you have to be strong and take back your power when it comes to the things you feel strongly about..
You are in the right here. Of course your kids shouldn't be exposed to his dating life and I'm sure everyone including your L and therapist would agree with that. The trouble is there is nothing that legally protects them from that, so you have to advocate for them. Besides, chances are he's so selfish and stupid that he probably doesn't even know if it is legal or not. Don't let him push you around on this. I know when I finally said enough and wouldn't fold, my husband didn't know what to do because I finally had changed the dance!