Guys and girls as friends

THe topic early this morning on radio was... can guys and girls be friends. Of course some callers said yes, some said no. But the best one was the caller who said : " IF a girl says her best friends is a guy, then tis fine. If a guy says his best friend is a girl, there is something going on !" Haha, come to think of it, its true in a way. I mean if a guy already has a gf, and if he says his best friend is a girl, we would tend to feel that its wierd. Maybe its because guys are less able to "control" themselves and remain loyal? lol