Who is in the wrong here?

My fiancee smokes pot and I HATE it, I mean, I have nothing against smokin' folk, but when he smokes, he becomes negligent, ignores me, and gets dependent on it and if he can't find any, he resorts to spice (incense K12) and that makes him downright disrespectful and careless to everything and anything that pertains to me. I asked him ( this was like 3 months ago) if he would be respectful enough to ask me before he just goes off and does it since it is something I really hate. I said "if you have the respect enough to ask if it would bother me, it would really make things a lot smoother". I am not trying to control him, cause he knows he does whatever he wants, I just want him to realize that something that makes me uneasy, should be discussed, as if my opinion on the matter is valid in whether he does it or not. So for the past 3 months, just about every time he wants to buy some, he comes up, tries to manipulate me with hugs and kisses and of course I say it is okay, I have been so lenient and okay with it cause he has had the respect to ask me. Yesterday, he dawns on me that "it doesn't matter what you say, yes or no.. I am going to do it anyway cause I neeeeeeeed it, my job sucks" I said "so why did you ask me in the first place!" he said "cause you asked me to, so you would think your opinion is valid when it really isn't, you can't control me, I am going to do what I want, and when I want, you have no say" I said " I don't want to control you, I just don't like you doing it! What, you think I wanted you to ask me cause I just wanted to hear the words?" After all that, with no solution, we played the silent treatment, went to his moms for a feast, at this time he was starting to be nice to me, as if he was going to be sorry. On the way back, we drove to walmart and parked right along side his Cousins car (his cousin was in the car) my fiancee hands me a 20$ bill and asks me to go shopping for food, I look dumbfounded as to why we are here, then he gets out of the car to get into his Cousins car and I go "are you kidding me? After this huge, unsolved argument that took the whole day you are going to go smoke up in your cousins car and send me to buy milk and eggs.." he goes "yup, well if you want to buy cookies, go ahead, I told you I am going to do what I want, see you in a bit". So now I am infuriated by his audacity, who is in the wrong here, and who is in the right, if anyone, just be honest. I need someone to make sense.