As a young engineer, one early evening i rushed into a BA aircraft closed up at a gate to carry out a cabin inspection (well before ETD, waiting for crew, fuel etc) only to find a pair of cabin crew having it off up against the forward cabin bulkhead .. quite an eye opener for a 19 year old!
Many years later, i was approached by an instructor employed by a mate of mine with a peculiar request: to hire my Aztec, with second row seats removed and with a curtain of some sort erected behind the pilot. After quite a deal of probing around this odd proposition, the guy sheepishly advised that he wanted to start a 'mile-high' charter operation. I wasn't interested thank you very much .. i had far better uses for my aircraft than as a screwing venue!!