I'm going to get between my ex and his more recent ex
Is  there a reason you want to mess with the ex's?
I knew that ex was bad news and it's karma that she's getting what she deserves.
You shouldn't come between two people. Let them figure out their own problems. If you get involved, it will just make the situation messy for everyone and no one will appreciate that.
Why does everyone try to tell me how to live my life?
I think you should move on. If they are not in your life it is wrong to start drama and create problems for others.