"Maybe we're all too hung up about the naked body. In this case just his underwear. "
This...
We don't know his circumstances or what kind of day he had that led him to have to change into his work clothes in a parkinglot. Hopefully, he didn't lose his housing and is one of many who still work, many times low paying jobs, but is stuck living out of his car. Live and let live, peoples. And, If my kiddos had seen him, I would simply have explained just that. No need to pass impossible puritanical standards on to the next generation... we've already left them with enough to have to clean up... this is kind of silly.
~Jean