Possible boundary 1: I would tell him in a short and civil email that you have decided that you no longer wish him to be present at the classes and will be taking a best friend along instead.
You could extend this to all doctors appointments until the birth if you wish.
It's your choice of course, but I recommend this because your pregnancy is YOURS and it is about YOU and it is important that you live it without turmoil. Your needs come first, not his wishes. I strongly think your H doesn't NEED these classes since he's already made it clear he's going to be an involved father (albeit part time).
Start treating him like a divorced dad. It might wake him up and give him a taste of what is to come.
