I already warned him once in the other topic, but I know people are going to do what they're going to do. Everyone has their own vices and demons to contend with. I'm no different. Most smokers know what's going on in their bodies when they smoke, just as I know what happens in me with every swig of alcohol I imbibe. If the pleasure is worth the risk to the person partaking, then it's up to them. When I was a MUCH higher consumer of alcohol in the past, I knew exactly what I was doing. It's presumptuous to think that smokers, drinkers, etc are ignorant of the risks, when so much information is out everywhere telling them just that. To caution at the beginning is one thing, to presume and nag if they decide to take it up or not is another.
Believe me, I had to learn this myself from living 35 years with smokers. They know. They really do.