How to get revenge on this backstabbing jerk?

So I broke up with this girl in January and we're really good friends now. We have best friend bracelets and text every day. She started going out with this guy who was my best friend. He became a real jerk and doesn't let anyone near her. He's always calling me gay or a homo, even though I'm not. Long story short, he's not my best friend now and I need some really good revenge for all of his bad actions. He's even slapped/hit me. I can't do anything too grand because school's just been let out for summer but I need something that'll put him in his place. He also swears at me quite frequently. Just to describe him, he has short brown hair, an ugly face (kind of droopy?) and he's fat. Not bellyflab fat but he is quite plump. I've already put his phone number and email into Mystery Seeker. Please help me!