If you're dealing with an infidelity, no matter what side you're on, this is one of the best books out there. There are so many books out there on this topic; the market is literally flooded with them (speaks to the amount of cheating that must go on, doesn't it?). It's difficult to really know what will have concrete advice and explanations. This books is good for the "betrayed," because it doesn't blame the victim, it helps the person heal whether you're staying together or not, and it helps give a feeling of vindication. For the unfaithful, it explains how situations can unintentionally lead to a situation where cheating is more likely, explains emotional affairs for those that just do not get it and think it's only cheating when you've done all there is to do, and gives steps on how to protect yourself against faltering. If both parties are willing, this book is a great tool to read along with your partner, to work through the trust issues, to work through any other issues that may have contributed to the cheating behavior, and provide a healthy way to work through the affair(s) together and provide some healing. But it's just as important on an individual basis to read, and even if you've moved on from the relationship, it is one of the best books out there on infidelity. Everyone says they'd walk away when it happens to them, but it's not always that simple if you find yourself there - this book can help you deal with a situation you may have never thought you'd find yourself, and ease some of the pain that is on both sides.