Talking to girls

Question

Talkign to girls is a "controversial" issue. I personally follow Rav Moshe's Teshuva and do not tlak to any girls. However, one of my friends has a close friend who is a girl. He claims that there is nothing special about his realtionship with her and says that if she were a boy, it would not be any different? Is such a thing possible or is he just foolign himself? If it is possible, is it permissible?