At my old climbing gym job we all had keys, and once in a while we'd open up the place very late at night so we could climb with some of our friends. The place had a cathedral-like feel at night with its wide open spaces and flood lights stretching into the dark. One night at around 1am, we were climbing with a few local friends and our boss happened to stop in. The last person we expected to see in the gym in the middle of the night, but in retrospect I suppose it was inevitable. Walking in on your employees hanging out in your business with a bunch of strangers must be unsettling as an owner, but our boss handled it with class. He actually asked if we'd had our friends sign waivers, and he had the presence of mind to never follow up and look for the waivers when we told him that of course we had filled them out.