While most people agree those in committed relationships shouldn’t cheat, it still happens all the time. Infidelity has inspired great pop albums and toppled political careers, but do we really understand it?Esther Perel, renowned couples therapist and author of Mating in Captivity, is sharing what she’s learned from 10 years of researching and helping couples around the world work through the pain of their affairs. Her new book, The State of Affairs:…