They don't have such weaknesses

Funny story about that.

When I was a kid, 15+ years ago, my parents told me about somebody that did that here in Texas with their son.

The father took his underage son to a restaurant and was able to get him a beer. During the meal, the father went to the bathroom and the son took a drink of his beer. A cop was sitting nearby and arrested the kid for underage drinking because the father wasn't in the presence of the son so it was no longer "supervised".

Wisconsin has the same law and includes spouse of drinking age.