I have a Sis-in law who forewarned us, the first time we visited the beach near their island cottage, that the the beach had an "optional" tradition, and that "some of the wrong people" tended to go nude. (Don't panic, she wasn't being that serious, and she is far from a real prude). My response was to the effect, "Do you mean someone is making the people who don't want to go nude do it, instead of the ones who want to?"