Maybe now he's moved out just let it go. Sometimes it's not worth saying anything. He's young and I'm sure he won't be like that forever. Maybe a joking kind of ribbing would be better than a lecture - what's done is done. It would have pissed me off too!
I most likely will. We will just go out and enjoy a good lunch and hit an indoor flea market we enjoy. HE seems to be doing okay keeping his own place u pfor the most part.
Don't worry, you'll have your revenge when one day he moans to you about his kids making a mess, and you'll raise your eyebrows and say something like: 'oh, I remember SOMEONE like that!' and he'll realise and appreciate you even more.
That will be fun!