Friend Problem!!! Please Read!!!?

Your friend "Sammy" is definitely being unfair. If she already has a boyfriend, she should not care that you date someone. I could see where if she was single and had a crush on the guy she could be mad at you. But she definitely should not have told him that you liked him when you expressly told her not to. And she should DEFINITELY not be going around behind your back calling you a slut. She's betraying your trust, and maybe you should rethink having her as a friend.