Guys, I'm curious. If you have a girlfriend who you love is it still possible to little crushes on other girls?

I have a friend who has a girlfriend and openly loves and I totally believe it, but I don't know... he just gives me these really dreamy looks sometimes. he asks me to dinners, to walk in parks, we hang out sometimes for nearly 6 + hours a day... he has never verbally alluded to anything but my womanly spidey senses are detecting a hint of a crush... so is it possible to be totally in love with your girlfriend but have minor insignificant crushes on other girls?