Hes a ****, help me break them off?

Some people are like this which does suck alot, I mean its really hard to get through with them, its usually because they think they are worthless or that the person they are dating is the best they'll ever get, I mean think if you were in her shoes lets say its your first boyfriend or girlfriend and there always mean to you but the way you look no one else wants you, so would you want to be a satisfied fool or take a small chance of being happy? She probably doesn't want to be without anything and so if she has to suffer with it then so be it. Although I dont know what she looks like that is usually what its about. The easiest way would probably to be alone with her and to really tell her straight from your heart of what you think, and make her listen, tell her to listen before she says anything back. And really tell it from your heart not just what you think but really that it hurts to see and other things like that, thats as a friend you dont want to see your friend abused by someone so undeserving, I am a guy myself so I dont know how it would feel being the girl but I dont do things like that I find it pretty mean and sick, I mean a guys mind does function just by what we see so sometimes its hard to control but if you actually do like or even love someone you would be able to have the strength to control yourself from touching other people while your dating, as for being bi, its so common that I consider all girls bi, and I think its cute to see 2 girls together and in general I find bi girls sweeter alot of the time because they like feminine passion, all in all good luck with your friend I hope it works out.