I disagree in part because, while I feel that finding other people attractive is natural (after all, can we honestly say that the eyes we first saw our partner with are now blind?), I find that lusting after other (in this case) women BLATANTLY is too much.
I'm in a relationship now in which I am dealing with this very problem. When we first met, we were truly swept up in the throngs of love. After a year and a half, I noticed that he would stare at other women a lot when we were out. My belief is that some things are better left unsaid (and unseen).
The fact that this man, who I believed was my soul mate, could not sustain his attention on me when we were in public, really hurt my feelings. It isn't that I do not notice other men. But I would never be so rude as to do it in front of him. And that is not saying that I endorse lying. Some things are private....why engage in a behavior that is hurtful?
And for those guys out there who think that I'm just another insecure woman: After a few months, I started watching other people when we were together too. Not to get back at him but because I was sick and tired of focusing on him and seeing him look at other people. What happened? He started to get upset because I wasn't paying attention to him!
When it all comes down to it, we want to be with people who we feel cherish us and hold as #1. Once those private actions are brought out to the other person, it is reasonable that that person will begin to question the foundation and desirableness of staying in that relationship.
My boyfriend says he loves me and wants to be with me always...only he doesn't know that because of this behavior (and others, of course), I'm seriously considering not being with him.