Visitation question ( supervised visitation )

Say my sons dad has supervised visits in my home supervised by me or my parents.

Is he allowed to bring his friends with him?

I already told him no to bringing a girl with mental issues with him, now he’s bringing another friend and I’m not 100% sure I’m okay with it mostly knowing this is also his second time meeting his son in 9 months. He’s saying if his dad can’t be with him, he wants a friend with him. The only reason I have to have someone home with me is due to the history of him being so mean to me and intimidating me.