Peggy Vaughan, author of “The Monogamy Myth” and “Beyond Affairs,” died at her home in California on November 8th after a four-year battle with cancer. Her death came on the day CIA Director David Petraeus submitted his resignation. For more than 30 years, Vaughan was the go-to person for reporters, producers and the general public searching for answers about why people cheat and how to live beyond the affair.