How would you feel?

It seems to me every time me and my significant other go somewhere his eyes are wandering. To the point where I have to literally say something to him about it for him to stop. He is constantly checking other women out in front of me and acting as if it’s not supposed to hurt me. I know how insecure I must sound but if only you ladies knew the half of what he put me through this is just flat out embarrassing to me and beyond hurtful. When we got home and finally talked about he admitted to looking at her ass but I saw them make eye contact twice I asked him if he knew her and he told me no I don’t know if I one hundred percent believe that. Someone please tell me I’m not overreacting. I know That all men look a glance is nothing serious but this is so much more than just a glance And it’s literally every single time we are in public.