Though we don't often use the word "normal" when talking about guy behavior (hee!), the short answer here is, yes, it's not unusual for totally faithful, committed guys to still check out other girls now and then. The key concern shouldn't be whether your boyfriend does it but how often he does it, how overtly, and how he treats you in general.

It sounds like your guy isn't gawking at every female who walks by, which would certainly make you feel uncomfortable and weirded out. If he hasn't been über-obvious about taking a few casual sneak peeks at other people, he scores a point with us. (Some guys' roaming eyes are so obvious it's insulting.) And since he's been open and honest about it, he scores another one. There's no reason to doubt him when he tells you he's not about to cheat, and it sounds like you two have a really strong relationship, which is awesome. If he suddenly started leering at every girl in his vicinity, not even attempting to be subtle, you'll have to have a serious talk with him. Luckily, your guy sounds light years' away from that kind of sleazy behavior.

But be honest. Have you never looked at another male since you started seeing your boyfriend? Not once, even when you were out just with friends? We're just saying that this behavior isn't only reserved for the males among us! There's nothing wrong with looking; it's totally natural to notice attractive people. It doesn't mean we're bad, or about to cheat, or that we don't care enough about our significant others. It just means we're human.