What to do?

So my boyfriend started smoking again and I can’t stand it, I’m totally not down for it. Totally disguised by it. It’s just unattractive to me. I feel like he lowered his standards. I told him how disappointed I am in him, and even tried to understand why he wants to do it but I feel like I just can’t accept that. I don’t want to leave I just want him to make a more positive decision but he thinks I’m just being judge mental. I know it’s his life and I want him to be apart of mines but I dont know if I can deal with that.