I wonder if it is possible that he made fun of your DBing because he feels bad about how selfish and mean he has been in the relationship? Perhaps it bothers him that you are so clearly taking the high road and he has so clearly taken the low? Distracting himself from thinking about his faults by tearing you down?
I don't know. I'm new to your situation and it is kinda dangerous to try to get in someone else's head even when you know them very well but...
Hang in there. Maybe this is just a one time thing or maybe not. I almost think that if he continues to tear you down for DBing that that supports my guesses.
I guess my opinion is different than some of the other posters. "Strike while the iron is cold." Don't make any decisions about ending the relationship until you've had some time to cool down and regroup a bit.
