Why does this guy check out any girl who is around? While he's holding my hand?

I am at a loss. I have been seeing this guy for about three months now, it's not to serious but it is getting there. He tells me he has relationship anxiety and inadvertently it may be to much for him to put a label on our relationship. I think it's absolute b.s and I'm getting to the point where I can't take much more inconsistency and lack of interest. Whenever I'm with this guy and any girl, i mean ANY girl walking down the street or any girl just around he stops whatever he is doing and ogles her, I don't understand. It hurts me so much to have him do this and even though were not officially dating we are still fully seeing each other and have a connection. Why do some guys do this.. is it insecurity? does he need reurance that he is attractive to have any girl that he oogles look his way? I get it he's a guy and if an attractive girl is walking down the street he may once in an effing blue moon maybe look her way, but all the time? No. I am an attractive intelligent woman and I know I don't deserve to have someone do this to me, the perpetual motion of women gazing is one activity that I won't partake in and I have openly articulated my concern but he is completely ignorant with his action in not doing it. It has to be insecurity, but I am still conflicted with the reasons to why. It's embarring, having him do this and I can't say that I can take much more because i was never the type to appease.