He should be made understand that he can't change you doing your d, and learn to live with it. I mean, yeah ok i smoke weed but a few of my friends do a drug I would not in the near future touch and that's ok. I'll be there when they're really go to far and that's what they can use best then, they'll learn. Anyway your friend may be a very cool guy with worrying a bit abolut you. marijuana isn't too much of a danger, but maybe he believes it's like a portal drugs and that kind of shit.

And let him hang out with the sluts, you don't have to follow him every where he goes. There's a positive side to not always hanging out with eachother.

Peace
Wybe