There isn't much you can do sadly. A teenager is smart enough to keep his traces secret and dumb enough to think he'll get rich gambling. Talking to him is the only option in a situation like this. If he somehow gets what you are saying, he will never ever become addicted to gambling again. If he doesn't, then you are looking at another poor lost soul who's going to waste his all remaining life on gambling. That's the problem with some people. They hear the words but their brain can't comprehend their meaning. Smart people know their limits, they instantly recognize it when they see a person that is smarter than them. Dumb people think they are running the show.