To this day I still have issues with my own mother who introduced me to her then boyfriend she left my father for and I was 5 and my sister was 7. I am almost 40 and still remember it like it was yesterday. My Father, however, only allowed us to meet my now stepparent after 2 years of seeing her and he knew he would marry her before he introduced us to her, I was then 7 and my sister 9.
I have been there. So has he.... His mother married 5 times and he had 6 Dads by the time he was a teenager... frown
Maybe you could mention this calmly, both of your histories, to H when he is in as reasonable a mood as possible and he will possibly hear you. Make him aware that it is NOT about you thinking you have any sway about whether he dates or not but about HOW MANY PEOPLE are dragged through the children's lives. I don't think it would hurt to bring up that the point was also made in the divorce class you took.