At first yes it matters a lot, but once you get use to her you just accept it. That's how it works. He is not going to verbalize it because he may not want to hurt your feelings, and after a while when he gets use to it he will forget about it, so don't worry. No body is going to remind him either because everyone knows that you should not speak bad about your friend's girlfriend and if someone speaks up, he will probably break relationships with this person for being a douche, so you are safe there. The only one that can remind him is you and he will deny it, but if you insist and insist he is going to get tire. So what you need to do is not talk with him about it much once he is past the first stages of acceptance.
I remember I had a fat girlfriend and I use to travel, I was away for 3 months and we only got in touch by phone, I liked her, I never cheated on her, every time I went back home I knew I had to kiss her, and I was gross out, but then I remember how many times I done it it in the pass. So I forced myself to kiss her more and longer so I can get use to it fast, in about two days I was back in liking her a lot.