reverse-slumming
Hanging out in an enclave of the rich when you yourself live in or are staying in a distinctly more modest neighborhood.
While visiting a friend in San Diego who lives on Ladrillo St., I spent an afternoon walking the streets and bluffs of La Jolla. When I asked my friend to drop me off on his way to work, I said, "I'm going to go reverse-slumming in La Jolla."