In her book Affairs, Emily Brown talks about the category of empty nest affairs. An empty nest affair is a misguided attempt to avoided dealing with fears that have been ignored for years. This is usually a man who has been married over 20 years, but it can be a woman as well. He begins to perceive that there isn't a strong bond between he and his wife.
This man generally believes he can attain the perfect family through some formula. This leads to a sterile, hospital clean environment instead of an emotionally connected one. They most likely partner well on the practical day-to-day activities of living. He lacks connection with his wife, but doesn't know how to address it and finds it with an affair partner. There is usually a deep emotional attachment with the partner.
Like the name indicates the children were the focal point of the relationship and are in their teens or out of the house. Without them it doesn't seem like there is much conversation. He may find a woman much younger to try to recapture the excitement or romance he feels he missed out on in his youth by being a dutiful father and husband. He also may feel like he wants to get some things done now that he won't be able to do as he ages. Like all affairs it brings a false sense of life.
This man may live a dual life for many years. He wants to leave his wife, but finds it difficult to do so. She puts up with his absence. The fear of not having a family is greater than them dealing with their situation by making it better or going ahead with a divorce.
The man is usually chronically depressed in these instances. He most likely is doing well in his career. He feels stuck. He hasn't had the courage to face the status of his marriage head on one way or the other.
The wife usually takes blame on herself for any problems in the marriage as in she must have done something wrong if her marriage and family isn't up to her ideal. She sees herself as the center of everything in the family. This household generally avoids dealing with conflict on any signicifant level. They are both 'nice' people even though she may be perceived as a nag at home.
They also avoid any real intimacy. Talk of the future centered on the kids not on their hopes and dreams as a couple. To let each other into their inner worlds is a frightening idea.
With empty nest affairs there is hope for a revived marriage if husband and wife are willing to make the emotional commitment to the relationship. The big cost for the husband will be losing his affair partner which is where he has found life for several years. For the spouse it will be breaking through the denial of what a truly empty marriage she has had.
Without this emotional investment the prognosis is divorce or continue living the facade of a marriage.