The book you're referring to is likely 'The Adulteress' is not a book by Ernest Hemingway, however, I found that 'The Garden of Eden' has themes related to adultery. Assuming that's the case, here's a summary: The story revolves around David and Catherine Bourne, an American couple who travel to Spain. Their relationship is put to the test as they engage in role-playing games that blur the lines between reality and fantasy. As the narrative unfolds, the couple's marriage is threatened by Catherine's increasing desire for independence and her attraction to a young woman. The novel explores themes of love, identity, and the human condition. If you are looking for a different book, please let me know.