This is actually one of the best books I've read in a long time. The characters were engaging, the dialogue witty and the storyline somehow both unusual yet believable.
Lucy and Owen are a married couple with a five-year old autistic son, Wyatt. They have moved from Manhattan to the small town of Beekman in the Hudson Valley. They traded in a cramped apartment for a large old house where they even keep chickens. Owen continues to work a couple of towns over as a head hunter while Lucy cares for Wyatt and their home. One night over drinks their friends tell them about a gay couple who have an open marriage and all four discuss the merits of it. So Lucy and Owen decide to try it - they set out the rules of a 6 month arrangement that allows them to sleep with other people.
We spend most of the book learning the consequences for each of them, and their marriage, of this arrangement. Owen finds a partner first, Izzy, whose ex-husband describes her as "five kinds of crazy" - and she is. But somehow Owen can't extricate himself from the relationship. When Lucy is certain Owen has started sleeping with someone else she discusses it with a friend who sets her up with Ben, a recently divorced man living in New York. Lucy becomes attached to him and invents French classes which allow her to travel to New York weekly while Owen is in charge of Wyatt.
But not all of the book is about Lucy and Owen. We also see a lot of Wyatt - his behaviour seems comical from an outsider's perspective yet you can certainly see the challenges he poses for his parents. We also meet other townspeople - some of the mothers at the school like Claire, Susan Howard and Sunny Bang (Lucy's best friend who fixed her up with Ben). There are also scenes with the town's resident billionaire, Gordon Allen, who is sick of his trashy fourth wife but can't figure out how to properly divorce her when, in a state of delusion, he never had her sign a prenup. And now he wants not only to protect his fortune but to have primary custody of their son. He leads the charge to get rid of Wyatt's kindergarten teacher, Mr. Lowell who has decided to become Mrs. Lowell.
Susan Howard, who is involved in an unhappy, sexless marriage of her own, leads the protests to have Mrs. Lowell reinstated. She beseeches all the men in the town to wear dresses, with limited success. This campaign culminates in the most humorous scene of the book - a ceremony where all the kids in the town bring their pets to the church to be blessed. The mix of cats, dogs, chickens, goats and even a llama is wonderful.
In the epilogue which takes place about 15 months after the arrangement ends, we see what has happened to all of the characters.
I highly recommend this book; I couldn't put it down.