Your boyfriend looks at other women. You are sorely mistaken if you think otherwise. He may not sensually undress them with his eyes or have secret, dirty and sexual thoughts about them in his mind, but he still looks...he still notices...he's still a human being. Nobody is exempt from human nature. Not me, not you, not your boyfriend - not anybody in the world.
And, love has absolutely NOTHING to do with "looking." I love my girlfriend and have zero interest in anybody else, but if there was an attractive, half-naked women walking near me (whether my girlfriend was there or not), I wouldn't be able to help but notice her. Just like if there was an attractive, half-naked man walking near her, she wouldn't be able to help but notice him. Would we necessarily want to be looking? No, we love each other and have no interest in being with anyone else. But, we still look. And, there's nothing wrong with it. Is it anything to get mad or jealous about? No, absolutely not. Why? Because, it's human nature to notice the things around you, especially other human beings.