I'm sorry but every guy is different. When guys look at you, some will look away because they don't want to be embarrassed I guess. If a guy is taking to you a lot than a normal stranger would, than maybe. But its different usually for each person. Like I personally only talk to girls I like and have an acquaintance with already, not complete strangers, but I don't "check them out," like stare at them, because that's kinda degrading, and intimidating, in my opinion.
It truly doesn't matter how young or old we are, we as men are typically not any good at expressing how we feel. Perhaps it's because our parents don't teach us how (because obviously our fathers...