Stephen McCauley’s “My-Ex Wife” is an elegantly written comic novel. The surprising emotional depth throws this book to the top ranks of 2018. The AIRBNB observations are hysterical. This type of advice is given to increase AIRBNB reviews—“Just keep adding tons of throw pillows. It makes gives the occupants a homey feel. And if they ask for anything or complain about something just give them extra towels. They will shut up.”