Catty I'm sorry for your loss.
As I said, most if not all smokers start as a young teen. Smoking is a drug. It's a highly addictive drug that many doctors agree addicts will fight against for the rest of their lives. Show me any young teen that will read warnings and say oh, I won't smoke then.
It seems sometimes that to non smokers it should be the easiest thing in the world to do. Just stop. Except it's not that easy. Out of the twenty most dangerous drugs in the world, smoking is at number nine.
Catty, the above is not meant for you. But I will say that whilst the warnings may just have made your relative want to stop, doesn't mean he actually would have been able to.
Most smokers know someone that's died of cancer. Same as most non smokers. However cancer is not a smokers disease. Smoking increases your chances, but cancer was around long before smoking. And a lot of people have the mentality of, oh but that would never happen to me. Most of us think we are invincible until something scares us.
Smoking generally takes a long time to kill. If it does at all depending on your luck I suppose. Being in a domestically abusive relationship however, can kill overnight. One punch that finds its mark.
If being in a relationship with someone that smokes is abusive, don't get in a relationship with someone who smokes. You don't get to meet someone, get together with them then decide you hate smoking. Just don't do it. Of course there will be the odd few that started smoking after the start of a relationship. But statistically most smokers start as teens. And you don't get together with someone to change them.