Lol need some help

I need some help figuring out how to get someone back. Heres the story, my neighbor "M" and I have been friends for a while and my older cousin is also good friends with him. We all hung out like every weekend and just got a bottle lol needless to say we had some good times. But about 2 months ago he started toking, me and my cousin always had but never brought him, not yet at least he was dumb and we knew he'd get us caught. But anyway this kid has no will power and is just dumb he became a real fiend and would come over everyday and pull the ol "I'm so high" routine, we would just snicker and ignore him till he left.. So I guess he assumed he needed new Close friends so he met some kid "A" and started going over there everyday smoking and what not. Side note- I'm all for smoking trust me but not for doing dumb shit. Anyway he would always come over with stories like yea we got high and rode dirt bikes down the major highway in my town, and just dumb shit asking to get caught. So u disconnected myself with kid and thought fuck it I don't wanna get in trouble for this kid he's fucking up. Etc etc a few weeks go by and my cousin calls me and tells me M got caught by his parents and M's dad is going to have my cousin arrested if we see him again. And now we are where we are but it didn't take Lon to realize this kid A was the one who got Milton started on smoking and kept urging him on to keep doing, not gonna put either of there ages or mine but know its a little off but were family friends this A kid is older and it's weird.

 

And now he keeps trying to continue fucking up M's life and whatnot an it pisses us off. M tried to tell him to fuck off but he didn't and now we gotta do something. This kids a drug dealer and that was one of my ways of getting him in trouble but I don't wanna deal with police.