Couples have boundaries as to what is and is not acceptable in their relationship. At times these limits are defined very clearly and discussed openly. Other times, there are differing assumptions about the relationship boundaries. Infidelity occurs when a boundary is broken. While there are differing forms of infidelity (e.g. one night stand, years long emotional and sexual relationship) betrayal is a common theme. Couples therapy is an option after a relational betrayal to help establish: What happened? How did we get here? Where are we going now? Are we going together? What is required to protect the relationship from future boundary violations?
Infidelity and Attachment Theory
From an attachment theory perspective, infidelity can be understood as a threat to attachment security. In other words, the betrayal of infidelity can leave injured partners questioning: Do I matter to you? Do you care about me? Are you here for me? Can I rely on you? Do I know you? Are you in this with me? Will you show up if I'm in need? Injured partners may find themselves frantically trying to re-establish security in the relationship in order to quell the discomfort of disconnection. Alternatively, some injured partners try to rebuff their own fears and needs. Many injured parties vacillate between urgently trying to engage their partners (e.g. waves of intense emotion, anger outbursts, seeking sex, questions, demands, stipulations, and ultimatums) and detaching from themselves and the relationship.
The partner who was unfaithful is also reacting to the rupture in the attachment bond. This person may try to repair quickly to feel 'normal' again. He or she may feel guilty for hurting their partner, but unsure how to convey this clearly. The partner who was unfaithful may feel angry, alone, and/or confused. How many times do I have to say I'm sorry? Will she/he ever let it go? I can't go on like this forever. I need to know if she/he will ever forgive me and want me again.
Couples therapy, from and Emotionally Focused Therapy (EFT) model, focuses first on giving each partner space to share how they are impacted by what has happened in the relationship. Ultimately, each partner needs a map for: how the infidelity came to occur, the pain of the betrayal, and how to heal the wound together.
Snyder, Baucom, & Gordon. (2007). Getting Past the Affair. New York, NY: Guilford Press.