Obviously the parents don't know. I am one of those cheer parents who goes to every competition and stays with the kids at away competitions. We usually end up with a couple kids in our room whose parents don't go. There's a number of kids whose parents rarely go to competitions, especially the traveling ones. I can tell you that these are the kids that are usually sneaking out of their rooms late at night. I've had to chase a few down in the past. Thankfully I never caught them drinking, and it hasn't been a problem at our gym that I'm aware of, but I have seen it happening in other programs at competitions - especially Vegas and Worlds.

If they are out with the coaches and drinking, then shame on the coaches. You should not be in a position of authority supervising minors if you are breaking the law and endangering them, and yes, that's what drinking with them is. It's not a little harmless fun. It's a serious matter that could end up costing you your job and closing your gym down. Most are barely surviving financially. A lawsuit from parents or legal fees incurred from a possible arrest are a big, big deal and very expensive.