"Happy to see you." That's important to stress. He can't emphasize it enough! "Sad that he has to return to his awful uncle... but I hope he'll be able to find a path that makes him happy. And that we'll be able to stay in touch."

He might as well be honest about that. That's important. Still... "But I'm not disappointed you're here. So please don't think that. ...I don't know if you do, but on the off chance that was a concern of yours, I am nipping that in the bud right now."