What the others are saying is correct. As a man, you cannot refer to either men or women as girlfriends or boyfriends except as a romantic relationship. A man doesn't have a boyfriend unless he is gay. Rather, he has friends who are men. He has female friends, not girlfriends. This isn't true of women. They can have female friends that they refer to as "girlfriends." But male friends are still not called "boyfriends" unless there is a romantic connection. In the U.S., you have "buddies" or "brothers" -- male friends that you hang out with. Kind of like how, in Australia and Britain, you have "mates." There is no simple way to explain female friends, interestingly. Lol. Maybe because male-female relationships outside of romantic relationships are rare.