Check it:
tell her you'll stop smoking if she stops partying (which you've already said) but really get into that.
Usually they don't wanna stop partying and realize your weed habit is equal to their partying habits and therefore end up just comparing partying and weed as the same.
In the end it will end up as a don't ask don't tell thing.
It's the same with my gf. Yeah it sucks.. you're better off with a smoking gf.
Fuckin' tiring to smoke behind my gf's back.

I've always wanted a gf to be my smoking buddy.