Threesome

In Threesome, the fifth Jill Emerson novel, characters Harry, Rhoda, and Priss live in a troilistic arrangement and decide to write alternate chapters of their story, uncovering new revelations about each other as they read one another's work.

Originally published in 1970, it marks a candid shift in style, presented as a novel pretending to be written by its protagonists.

Part of Lawrence Block's early erotic fiction under the Jill Emerson pseudonym.