Well, how do you suggest I get a little revenge on my cheating girlfriend?

I am 14, i live in Canada, and I recently found out that my Girlfriend cheated on me. And I know the guy who she cheated with. I have 2 friends that have shown me messages from her to them, telling them what she did, so I know its 100% true. I am not looking for physical revenge in anyway shape or form, but a small amount of emotional revenge would be nice. Any suggestions? PS: Remeber that we are only 14.