Agree that you don't want it to get out of hand, otherwise you WILL have a physical confrontation. I mean, with some kids and parents that is kinda ok, won't happen again for long time/never. Optimally the dad is still young enough to knock said kid on ass. Something you can laugh about when THEY have kids.7th grade so this kid's 12-13? A simple spanking to the face should only be one prong of a multi-prong attack.
Don't forget in a few short years he'll be able to kick your ass.
He's probably intelligent just not using it for the right things.
Might need to experience what life is like when you do things half-assed or not at all.
Lots of manual labor for little return.
Maybe spend a week digging ditches and filling them up again in exchange for eating beans and rice with the lights on.
Then rewards for figuring out a way to better that situation.