I'm going after my ex-best friend's girlfriend.
Why do you want to go after his girlfriend?
He's trying to be my friend again after dumping me, now i want to take revenge for doing so.
Even though it's your former friend you shouldnt mess with his ex. It will make things complicated. It's not a good way to get back at him.
I didn't do anything major. How much harm can this do.
It seems like you are just trying to cause pain and hurt to him and that isn't the right thing to do. You need to leave this alone and stop looking to get back at people.