Dear GF readers; my husband is constantly comparing me with his exes

From a female GF reader

I am married to a man who constantly compares me with his ex girlfriend to my face!! Each time there is a little misunderstanding he constantly reminds me of how well his ex-girlfriend understood him and treats him. What does this mean and how do I deal with this? I am confused!! I have told him severally how well I hated it and he doesn't see a big deal in it, he doesn't even care how I feel about it. How do I get him to stop it?