I say good for the kid. He paid for his own stuff, instead of getting dad to do it. No different than if dad had forgotten the bread or something, and sent his son to get it, cept that the extra transaction will take like 30 seconds. Considering all the ‘Etiquette’ transgressions that happen in markets, that is a non-starter to me.

My personal favorite is the blank look people give when they are suppose to pay. As if they didnt realize the food wasnt free. “you waited till NOW to pull out your damn wallet!”