The Wife Between us by Greer Hendricks

When you read this book, you will make many assumptions.
You will assume you are reading about a jealous ex-wife.
You will assume she is obsessed with her replacement – a beautiful, younger woman who is about to marry the man they both love. 
You will assume you know the anatomy of this tangled love triangle.
Assume nothing. 

This book was fine on it's own although there were a lot of weaknesses in the plot. Those aside it would make an okay light beach read. However, I had just read the book "The Last Mrs Parrish" by Liv Constantine, which was almost the same story concept but written in a much better way and with a lot less weaknesses in the plot. Read this book if it is there but read The Last Mrs Parrish if you have the choice.