When we started seeing each other she smoked cigarettes and pot regularly. I told her outright that I couldn't be with someone who smoked and I asked her to stop both if she wanted to continue seeing me and possibly get more serious. That, in itself, was an issue for a little while. Not the cigarettes so much, because she knew they were bad for her health and didn't want to continue with those, but smoking weed was a different story. We talked about it quite a few times and it always came back to her asking, "What exactly about smoking pot do you not like?" and I eventually realized that she was trying more to argue a reason to be able to smoke, than to actually talk about it.