I'll second what RJ said. Stay away from him. I'll also add that if you don't stay away, you are an idiot. Being around him is just asking for (not deserving) more trouble, and bigger problems. Are you wanting to see how long it will be before he rapes you? You need to decide what kinds of things you have a zero tolerance policy for right now, and follow it.

And go be honest with your mother and tell her ALL the truth, so if he does end up doing something bad to you, she won't have to hate herself for advising you to keep contact with this ingrate without knowing the whole story.