Wow, 3 years is a long time. What is even worse than the pain you feel right now, is the pain you will feel when your spouses do find out. As you posted "all good things come to an end" don't think that this skeleton will remain in the closet. If you were willing to spend 3 years with this person, its obvious that you loved and cared for her.......one could go on to say more than your wife perhaps? Why not end things with your wife before pursuing another. Or was the whole 3-year fling you had just sexual, where neither of you cared about anything but that? Either way, you have my sympathy on the fact that you have lost someone you cared about for 3 years and you will hurt someone that you loved enough to marry and spend the rest of your life with. This is the double whammy! No matter what though, always remember that things will work out. No matter how bad today is, tomorrow will always be better. And to answer your question, the secret does hinder the healing process. Tell your wife and set things right now if you can. If you keep it from her it will only make things a lot worse. TRUST ME. Take care and good luck.