My Hubby is constantly comparing me with his exes

I’m married to a man who always compares me with his ex to my face!! Every time there is a bit of misconception he continually reminds me how well his ex understood him and treats him.  What does this mean and how do I deal with this? I am befuddled!! I have let him know severally how well I abhorred it and he doesn’t see a big ordeal in it, he doesn’t even give a second thought how I feel about it. How do I get him to stop it?