Why am I angry when my Girlfriend is around other boys?

Fear, your going to cause this fear to come true. The fear of her loss in your life and her talking to guys sends that fear into a fight not flight mode. Man up and be secure with being her man, or this fear is going to push her away from you. I love it when guys like you act this way, cause it's so easy to step in and sweep the woman away, so quit making it easy for other guys to get her by acting a fool.