Annoying

My boyfriend only wants to be around me if it's sexually related and won't talk to me or look at me otherwise... He rather talk to other girls than me and for that last few weeks everytime I wanna talk to him he says he can't talk right now and then I find out that he was talking to another girl all night... I know one of the girls that's like his sister but still I really love him and can't stand being away from him but it's so easy for him. What should I do?????