For homecoming my ds met up with a bunch of boys for dinner first, and one of the dads graciously stayed until they had finished ordering and then paid the bill.
It was a sitdown pizza place so it wasn’t a huge cost, but it was very nice of him to do that and spared the boys the awkwardness of trying to figure out the check.
I could see the parents doing that to avoid the kids having the challenge of dealing with the bill.