You seem to be a very mature 18 year old and you know I value your contributions on this site and you know I am especially impressed with how you handle your diabetes. But from a parents perspective, you can't (shouldn't) say to your child, "it is OK to break this one law, but not another law". Consistency is very important as a parent. In the OP's case, it is illegal for her son to consume alcohol. So his doing so has serious ramifications, not only for his body but in terms of his juvenile record as well. This is a very complicated issue and it is not simply black and white. And it is also not just about underage drinking. It is about the Law, it is about drinking and driving, etc. All those things come into play here. As you know, most teens don't sit around and drink one beer and play board games.