Poor form by your friend. I’m like you. If my kid brings a friend they are treated like family.
That guy sounds like the guy that goes on a group date and calculates to the penny the food he ate and leaves just enough to cover it and leaves the tip to everyone else. He probably never volunteers to he the banker.
When I’ve treated my kid’s friends they are almost always the first to say thank you. I know my kids have been treated the same by many of their friends parents.