How do I break up with this boy?!?!?

Ok so I have been talking to a boy that's a year older than me for about 6 months but not the whole six months cause I found out he had a gf %26amp; then they broke up %26amp; we got together %26amp; then he was acting really weird to me so we broke up %26amp; now we are talking agian. He says he wants to marry me. But he's not good for me. He also has a super bad temper and gets into fights all the time. (physical ones) I have been talking to this other guy that I really really genuinally like %26amp; he's the perfect guy((: But if he finds out that Ive been talking to him he'll literally try to put him in the hospital. Not joking at all. How do I break up with him?? I don't wanna cheat anymore.How do I break up with this boy?!?!?
pretend like your gonna give him a bj then bite it off. so then hell break up with you instead! your welcome...