Sounds like an immature idiot, to be honest.
As mentioned above - you can't just keep quiet, because as soon as you do, he'll realize how vulnerable you are, and will blame you for a lot of things he's done.
Honestly, tell him how it is. Tell him to quit acting like such a child and face the consequences of his actions. He doesn't need you there to "motivate" him..he's an adult, he should have been aware of the consequences had he not revised.
If he refuses to listen to you, then leave him. Personally, he doesn't sound worth the stress you're under.