The Alluvians are not people. They have traditions. Love pools form a fantasy in the mind. Daughters learn about male sexual behavior by subtle exploration using their fathers as a testing ground. A challenge presents itself. Two daughters against two others. Subtlety becomes boldness, turns into cunning. Certainly not about incest. Adults only? Different - cheeky, subtle, wicked in a sense, no real graphical sexual content except to explain how a love pool works and this as simply as possible, but adult terms are used to explain the principle. Hence best put this novel in the adult book shelf.