If you're paying all the bills then throw his *** out and his friends ***** out too. Get the locks changed. That should fix the problem.
Ya talk yo him before baby is here.
He's going to have to learn real quick that that cannot happen. Especially when you have a baby in the house that will be sleeping by like 7pm he can't be having people over.
Have you ever talked to him and set boundaries? Let him know he can't have friends over after a certain time. Let him know it won't be tolerated, and if there's other issues then when you talk to him about this then it would be a good time to discuss them