miaomiao said:
Why is it a bad idea? I'm sure he's mature enough to maintain a friendship with the girl even if its nothing more than that.
Rubbish, excommunicating is an excellent idea.
No trust me, listen to some depressing music, you know whatever the hell, get it all out, be sad for a week or whatever, but then completely change you, your scene, your attitude, and stay with friends and keep busy. Anytime you start to think of her or remember immdiatly stop it, stop it dead and think of something else, pretend she doesn't exist.
Eventually you will form a bitter and cynical attitude towards women which will serve you well for the next few years until you actually meet someone who is right, not just someone you thought was right.