Betrayal is one of the toughest things to live with. The terrible feeling that you have been let down in the most fundamental way by someone you trusted and felt entirely secure with. It is a truly awful thing, a traumatic and overwhelming experience. How are supposed to cope and live with it?
A marriage in which one partner betrays the other leaves a deep wound. The couple may find a way to stay together, perhaps because of the children, perhaps for other reasons, but the wound remains. There are times when the wound is painless, we may forget the whole thing and our lives feel normal again. Then, another day, it will flare up and the tormenting questions and feelings return again to devastate us all over again.
What can you do but live through it as best you can? There will be better days, days when the wounded feelings are less prominent, perhaps disappear. Betrayal is a terribly difficult thing to live with.