I have an idea for a story, but I don't know that I have the time with the other stories that I've been working on.
A community of people have been living on an island for three or four generations, after their ancestors were shipwrecked there decades ago. They've lived all their lives completely naked and freely practice incest and polygamy, with little to no knowledge of the world outside. (Think "The Blue Lagoon" but with more people, and the shipwreck farther back in the past.) One day a ship arrives with people from the civilized world, who are shocked by the islanders' "immoral" ways and are determined to "rescue" them, but ultimately end up being converted to the islanders' more liberated lifestyle.
If no one else takes up this story idea, I'll get around to writing it myself eventually, it just might take a while. But I thought it might be interesting to see what some other author might make from this prompt.