When Your Partner Says “I Don’t Know” About the Affair

Few answers are more frustrating after discovering an affair than “I don’t know.” The betrayed partner may be asking, Why did you do it? What were you thinking? Why didn’t you stop? What did this person mean to you? When the response is “I don’t know,” it can sound like avoidance, dishonesty, or an unwillingness to take responsibility. Sometimes it is. But there are also times when the betraying partner genuinely does not yet understand their own behavior well enough to provide a meaningful answer.

When “I don’t know” is genuine, it should be the beginning of the answer—not the end of the conversation. Instead of accepting it as a final response, I encourage couples to become curious about what is not yet understood. A more helpful response from the betraying partner might be, “I don’t completely understand why I made those choices yet, but I know you deserve an answer, and I am willing to work to understand it.” Questions can then shift from simply “Why did you do it?” to exploring what was happening internally and relationally: What were you seeking? What did you allow yourself not to think about? How did you justify crossing boundaries? What changed in you that made something previously unacceptable become possible?

It is also important to distinguish not knowing from not remembering. Betrayed partners frequently need factual information about what occurred, and repeated “I don't remember” responses can create additional distrust. At the same time, demanding certainty about details a partner genuinely cannot recall can create inaccurate answers simply to end the questioning. The goal should be truthful disclosure: what the partner knows, what they do not know, what they genuinely cannot remember, and what they are still trying to understand.

Healing after infidelity requires more than obtaining facts about the affair. Eventually, couples need to understand how the betrayal became possible and what must change so the relationship can become safer. I address these questions as part of the structured recovery process described in my book, Managing the Aftermath of Infidelity: A Sequential Guide for Therapists and Couples. “I don’t know” may be an honest starting point, but meaningful recovery requires a willingness to keep exploring until the couple develops a deeper understanding of what happened, how it happened, and what needs to be different moving forward.