The Real Cause of Infidelity
Cheating is a choice.
Posted January 20, 2026 | Reviewed by Abigail Fagan
Do you know which sentence people most frequently underline in my book, Healing from Infidelity ?
"Unhappy marriages don’t cause infidelity . Being unfaithful causes infidelity."
Why do you think this sentence has stood out?
First, here’s something many people (even some therapists) don’t know and is counterintuitive: not everyone who has an affair believes his or her marriage is unhappy.
In fact, data suggest that many cheating spouses report that their marriages are good, and that leaving their spouse was never a consideration. There are many other reasons people decide to have an affair besides unhappiness with their partner.
But beyond those who are in solid marriages and just looking for adventure, there are also people who decide to have an affair because they feel a void in their marriages.
Sometimes the emptiness stems from a lack of emotional connection — couples who spend little time together, or argue a great deal, stating, “We’ve grown apart.”
Other times, the void is due to a physical relationship that has become unsatisfying or non-existent. A sexual desire gap is a common reason people offer when they drift sexually.
Still, the primary reason people resonated with that sentence in my book is this.
Regardless of the challenging issues people are facing in their marriages, problems are not the cause of affairs. Let me explain.
I have worked with some couples who haven’t had sex in years because one spouse just decided sex was not going to happen. Many so-called “sex-starved” spouses feel lonely , miserable, angry, resentful, and defeated but do not go outside their marriages to find sexual satisfaction.
Conversely, I have also worked with couples who, despite fairly regular sex, when sex hasn’t happened often enough for one of the partners, the higher desire spouse feels entitled to find alternatives for more consistent sex.
In short, a lack of sex doesn’t cause infidelity; choosing to have sex outside of marriage causes infidelity.
This is not to say that having a satisfying sexual relationship or feeling emotionally close to your partner isn’t important. It is, and these issues must be addressed. But infidelity is not the answer to either a ho-hum sexual relationship or emotional distance. Fixing those relationship breakdowns is!
I think there is yet another reason people underlined that sentence.
Many folks seek professional help right after the discovery of an affair and are told by their therapists that the affair wouldn’t have happened if the marriage had been strong. Unresolved marital problems put the marriage at risk of infidelity, they’re told. Therapy begins with a focus on the vulnerabilities in the relationship.
First, this assumption is often inaccurate.
Secondly, even if there are major issues in the marriage that need to be addressed, the betrayed partner typically feels extremely traumatized early on and is either unwilling or incapable of examining problematic areas in the marriage at that time. Betrayed spouses feel blamed rather than enlightened.
It’s important for everyone to understand that infidelity is a choice. Affairs don’t just happen. Even if a person says, “I wasn’t looking for an affair, it just happened,” there is intention surrounding the slippery slope that led to the betrayal.
We all have choices. Taking responsibility for one’s choices is the first step on the path to true healing.
Glass, S. & Staeheli, J. (2004). Not 'Just Friends': Rebuilding Trust and Recovering Your Sanity After Infidelity. Atria Books. New York, NY
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Michele Weiner-Davis , MSW, is the Director of The Divorce Busting Center in Boulder, Colorado and Woodstock, Illinois and founder of divorcebusting.com.
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This article is part of the Bringwise Psychology Journal — daily insights on human behavior, mental health, and personal growth.