What should I do?

My fiancé asked me to look for his ring, that he thought it was somewhere in the room so I did. I looked through everything, including his backpack he occasionally takes to work. I found his ring in there but I also found a pack of cigarettes. He knows how I feel about smoking-his father and younger brother are addicted and I felt lucky he wasn’t even trying because he sees how his dad struggles to quit. His father even after breaking ribs and struggling to breathe couldn’t quit. Anyways, i don’t know how or if i even should bring it up. Should I be subliminal and just bring up a conversation about cigarettes? I don’t know. He’s obviously hiding it from me since he doesn’t do it here with me or around the house. He had asked me months ago what I would do if I found out he picked up smoking and I responded with “you already know I think it’s dumb and setting yourself up” and he said nothing to that. I had my suspicions then but didn’t push further. I worry he will become like his father and starting this young would cause issues for him later. I really dislike that he’s smoking and especially that he’s hiding it because he knows it’s wrong. It feels disrespectful. Even when we were just dating he knew how I felt about cigarettes. It’s like he’s always doing whatever to fit in or look cool.