Most Helpful Girl
Why would you want to be with a guy like that in the first place?
Think of yourself is what you should do, you already are angry at him, do you think if you and him stayed together he'll change? He's not going to change and you are going to get hurt over and over, then your anger will turn into rage, you'll start building up a resentment toward him that won't ever go away.
You're young, you don't deserve to be treated that way, don't let him think after cheating you'll still want him anyway, don't be a doormat for any guy.
Most Helpful Guy
Break up, why are you scared that he'll be with her? The problem here is if he cheated he didn't really care about you and then you shouldn't be giving a fuck about him.