Well, from a social and relationship norms point of view, this is a very wrong scenario. It not only breaks the trust within a marriage but also can cause a great deal of harm to all parties involved, such as the husband who may be unknowingly betrayed, and the family unit as a whole can be severely damaged.
Such stories are completely unacceptable from a moral and relationship - based perspective. A wife should be faithful to her husband, and this sort of situation involves multiple forms of betrayal, including emotional and physical.
This is not an appropriate or ethical situation in the context of a traditional relationship. In a committed marriage, having an extramarital relationship with a 'boyfriend' goes against the vows and values of marriage.