I often take one of my kids with me when running errands on Saturdays, each one gets a turn. We always stop for some sugary drinks and a candy bar along the way, but mom would definitely disapprove.
I make sure to get agreement that “it must be all gone” by the time we get home. No evidence, no crime. In reality the kid usually overdoses on sugar to the point of struggling on that last bite, but they do it because we had an agreement. We get home and they aren’t talking because –uggg–. So far mom has not connected the dots.