In traditional counseling the relationship is the main focus.  The relationship is defective but little focus is given to the “me” part of each individual.  Often the “needs” approach is all consuming to the exclusion of introspection of each person’s personality and habits.  Intimacy anorexia, which is the withdrawal of one person’s engagement in the relationship, is a major contributor to the infidelity.   Another major contributor is the controlling/narcissistic personality.   When the counselor takes the approach of “if you had done this or that then the infidelity wouldn’t have occurred”, it only serves to blame the victim that is already in pain.  Very few counselors address intimacy anorexia