When I was a kid (Im in my late 20’s, just starting to forget!) I didnt do the same thing as we always had an au pair who would be with us. a bit posh maybe, but looking back I would have given anything to have my mum or dad tell me off and have the interaction.
At the same time I always had the utmost respect for my parents. These days, everything has slackened off, even from 15-20 years ago. You now need to sit him down and talk it out as he may not really know why. They dont just know why despite maybe telling him a thousand times. At the same time, kids will be kids.
and scientifically, they have proven that as teenagers brains develop they do not think about why, they just do. All down to the chemical mix.