I've been through something very similar and what I realized is that although the mother's comments hurt, what really matters is how my fiance responded to it. Does he agree with her comments for the sake of appeasing her, does he stand up to her, does he just do nothing at all? Those are things to take into account because that is what will affect your relationship.

We've had a lot of discussions about it and in my case, although I was careful about what I said in regards to his mom, I stood my ground on what I expected and needed from him in order for the relationship to work. It took a few discussions before he finally got it. His mother will make the comments at anyone he is dating so it's not something you should take personally (easier said than done, I know. I have spent many therapy sessions talking about his mother). If you are serious about each other then he will be understanding of this and understanding of your needs. Is it possible for a T to help you talk to your boyfriend about it in a session? Talking to him certainly isn't easy, and the only way I was able to finally do it was when his mother made a comment that completely crossed the line and I got angry. If I had just been sad or hurt I would not have been able to say anything, but it was like I finally had enough. I didn't blow up at her or even at my fiance and I waited for the right time to talk to him about it, but I felt so much better after addressing it and it gave me the confidence to do it again. I also did a lot of journaling on it just to organize my thoughts and get any personal attacks towards his mother out of my system because I didn't want to bring that into the conversation.