When someone really cares about you, they act like it, and this also includes caring about your feelings.

If he knows (and he does, trust me) that it makes you feel uneasy, anxious, insecure, jealous, etc when he frequently mentions it, and he does it anyway, not only does that mean he doesn't care about your feelings, but it also means he is getting a kick out of making you anxious and jealous.

He's playing games. This is a red flag that you are getting early in the relationship. Your choice on whether or not you choose to put up with it.