Sex After Infidelity: Why Desire Can Vanish — or Suddenly Become Intense
Author: The Narcis editorial team · updated: August 2026
Clinical review: a practising psychotherapist
ENGLISH · Narcis editorial
What changes the picture
After discovering infidelity, one person may be unable to tolerate the partner’s touch. Another may suddenly want more sex than before the crisis. Both reactions can feel alarming.
Sexual response after betrayal does not have to match a moral position. Intense sex may temporarily function as a test of connection, a way to feel chosen again, competition with the third person, or simply a means of regulating enormous stress. Loss of desire may follow shattered safety, disgust, or intrusive images.
A small study of behavioral couple therapy found that couples dealing with disclosed infidelity began treatment more distressed than other couples but could still show substantial improvement. That does not mean every relationship should or can be saved.
Sex should not be used as the sole measure of forgiveness. You can desire a partner and not trust them. You can forgive parts of what happened and still not want sex for months.
Rebuilding intimacy starts with truth, boundaries, and safety — not with a demand to “get the sex life back to normal.”
How it shows up day to day
After infidelity, she suddenly feels intense sexual desire for the partner even though trust is shattered. It seems illogical. Sex may function as a test of connection, competition with the third person, or stress regulation. Strong desire does not automatically mean forgiveness.
When similar behavior means something else
Pain, abrupt change in sexual function, marked dryness, medication side effects, or other physical symptoms still warrant medical assessment. Sex therapy and medical care often need to work in parallel.
What the work can look like in therapy
In couples therapy, the therapist should not become a judge of who “should want sex more.” The task is to build a language in which both partners can discuss desire, disappointment, and boundaries without coercion or humiliation.
A practical frame without self-diagnosis
For “this topic,” keep four questions separate. Desire: is there internal interest in sex? Arousal: how does the body respond once contact begins? Consent: can either person freely say no and change their mind? Comfort: is there pain, dryness, bleeding, or an abrupt change in function? Then examine context — stress, sleep, medication, conflict, privacy, life stage. Psychotherapy can address fear, shame, relational scripts, and communication; it should not psychologize new pain or other physical symptoms without medical assessment.
Books and sources
• Atkins DC et al. Infidelity and behavioral couple therapy: optimism in the face of betrayal.
• Stefanou C, McCabe MP. Adult attachment and sexual functioning: a review of past research.
If this topic resonated — you do not have to sit with it alone.
Find a therapist for this topic →This article is for information only and is not a substitute for an individual consultation with a specialist.