Some people can smoke too much for too long, and ditching class a lot will land him a menial minimum wage job. It's okay to like the guy, but you might not want to be deeply involved.
Weed is something I can overlook, as is ditching. Just because he does it doesn't mean you have to. But if he's a pla<x>yer, beware. Don't give him anything good unless he's worthy of it, love.