"Sleeping Arrangements" by Madeleine Wickham

Madeleine Wickham is better known as Sophie Kinsella, author of the Shopaholic series! This book is about 2 couples both holidaying in Spain at the same villa - although both couple thought they were the only one staying there. Turns out the husband of one couple, and the wife of the other have a history together. A fun read, very enjoyable. Perfect for a sunny afternoon with nothing else going on.