Most Helpful Guy
Make him block her and tell him that if you ever find that he has spoken with her, or even looked in her general direction, you will either leave, or castrate him. THAT will give him something to cry about. If a guy cries of something like that, he is a really immature.
Most Helpful Girl
Honestly, the fact that you got furious when he did not even reply means that you're not over the fact that he cheated on you. Just compromise with him and tell him what you expect from him if you do take him back. From there, do not bring up the past. People make mistakes and if he does prove to you that he is a changed man, then trust him.