I know nothing about this book except what I read in this review. If the reviewer is honest, the publisher isn't. Of course, the publisher is Doubleday, which is probably about as mainstream (corporate, legacy, establishment) media as you get, so it shouldn't surprise me that its book cover appears to misrepresent the book's contents.
The book cover says it's a sexy romp. The book is a sexy death march.
The review is itself pretty racy, so you're forewarned, but it boils down to one essential point: The autobiographer has been miserable in her open marriage for decades but keeps doing it and, though admitting the sad details, can't see the sad whole.
The husband, meanwhile, has been having a great time.
It's no wonder the book cover lies about the contents. The contents are a repudiation of the idea that traditional mores are mere societal constructs. The natural law is written on the heart, which is then transmitted through the generations and centuries. We can jettison the transmission, but the initial prompting is still there: on the heart. In our human natures. We reject the transmission (the tradition) at great peril, as this woman's tortured existence shows.