If you REALLY dislike your partner doing something, should they stop because of you?

Just trying to get a general consensus here. It might not seem like a huge deal but my partner likes to smoke when he's drinking, like he smokes like a fkn chimney when he's drunk! And its only when he drinks which isnt that bad BUT I HATE IT SO MUCH. And he knows it, he has said he'll stop sooo many times and he just ends up doing it again and again behind my back. And it really upsets me. I found a whole packet and a lighter in his pocket after a night out and I was fuming. I dont think in a relationship you should tell the person what to do and order them around. Which is not what I like to do, but then i think he thinks he can get away with so much. And not to mention he's drinking all the time on the weekends these days and its always my job to go and save him, it makes me feel like such shit :(

Do I tell him it really bothers me that he goes against my feelings or am I being irrational and a whiny bitch?