I'm not going to let my bf meet his ex
Is there any reason to do things like that?
I hate this girl. She has caused problems in the past.
You can't really force someone who they can or cannot be friends with. If you control your boyfriend like this, there is a high chance he might break up with you.
I hate it when you try to explain me stuff. You can't control other people and I already know it.
Then why are you trying to? I think that you should let them be friends with who they want. You should not try to be so controlling.