Relationships that begin as affairs face steep odds. The most direct research on the topic, studying couples where infidelity played a role in relationship transitions, consistently finds that these partnerships tend to be less satisfying, less stable, and more prone to further infidelity than relationships that start on more conventional ground. That does not mean every affair-born relationship is doomed, but the patterns are strong enough that researchers have identified specific, measurable disadvantages baked into these unions from the start.
What “Mate Poaching” Research Actually Shows
Psychologists use the term “mate poaching” to describe situations where someone attracts a person who is already in a relationship. It is not a flattering label, but it captures the dynamic researchers study. Across three separate studies, people who were poached by their current romantic partner reported lower commitment, lower satisfaction, lower investment in the relationship, greater attention to alternative partners, and higher rates of infidelity compared to people whose relationships did not begin that way.1Journal of Research in Personality. What do you get when you make somebody else’s partner your own? An analysis of relationships formed via mate poaching Those findings held consistently across all three study samples, which gives them more weight than a single result would.
A separate study confirmed the pattern and added a troubling layer: people currently in a poached relationship tended to have a more extensive history of poached relationships, suggesting this is often a repeating cycle rather than a one-time event. Those with more poaching history reported poorer relationship quality overall.2PubMed. Once a Poacher Always a Poacher? Mate Poaching History and its Association with Relationship Quality The connection between poaching history and lower relationship quality was partly explained by a more permissive attitude toward casual sex, which itself predicts less exclusivity and less long-term investment.
In plain terms: when someone leaves a partner for someone new, the new relationship does not start with a clean slate. It starts with a demonstrated willingness, on at least one person’s part, to exit a relationship when something better appears. That willingness does not evaporate because the new relationship feels more exciting.
The Trust Deficit Is Built In
Trust is the recurring problem in relationships born from affairs, and it operates in both directions. The partner who was “won” through poaching knows, at some level, that their new partner is capable of pursuing someone who is already taken. The person who did the poaching knows their new partner is capable of being drawn away from a commitment. Neither of these is a comfortable foundation for long-term security.
This is not just theoretical. The research on mate-poached relationships found that poached individuals reported higher perceived quality of alternatives, meaning they were more actively aware that other potential partners existed and were appealing.3Journal of Research in Personality. What do you get when you make somebody else’s partner your own? An analysis of relationships formed via mate poaching Keeping one eye on the exit is not a recipe for deepening intimacy. It is a recipe for the kind of anxious surveillance that erodes both partners over time.
The dynamic is sometimes described as “if they’ll cheat with you, they’ll cheat on you.” That is overly simplistic as a universal rule, but the data does support a weaker version of the claim: people in poached relationships reported higher infidelity rates than those in non-poached relationships. Whether this reflects a personality trait, a relationship dynamic, or both, the practical result is the same. The couple starts in a trust hole and has to climb out of it while also building everything else a relationship needs.
How Cognitive Dissonance Masks Early Problems
One reason affair-born relationships can feel so intense at the beginning is that the human brain works hard to justify costly decisions. Leaving a marriage or long-term partnership for someone new is an enormously costly decision, socially, financially, and emotionally. The psychological discomfort that follows is well-documented: people who commit infidelity experience measurable increases in self-concept discrepancy, psychological discomfort, and negative mood.4Journal of Social and Personal Relationships. It did not mean anything (about me)
To manage that discomfort, the brain reaches for strategies. One common approach is trivialization, downplaying the seriousness of what happened. Another is attitude change, shifting how you view fidelity, your former partner, or your own values so that the affair feels justified. Research on infidelity and cognitive dissonance found that strategies like self-concept change, attitude change, and denial of responsibility were effective at reducing psychological discomfort over time.5Journal of Social and Personal Relationships. Justify my love: Cognitive dissonance reduction among perpetrators of online and offline infidelity
This matters for the new relationship because it means the early period is distorted. The affair partner gets idealized partly because the brain needs them to be ideal to justify the upheaval. “I destroyed my family for this person” is psychologically unbearable unless “this person” is extraordinary. So the brain obliges, inflating the new partner’s qualities and minimizing their flaws. When that inflation fades, as it always does, the couple is left with whatever the relationship actually is, minus the romantic fog that helped justify its creation.
Social Disapproval and Isolation
Couples who form through affairs often face significant social disapproval from friends, family, and community. Research on what psychologists call “marginalized relationships” shows that social disapproval has a measurable negative effect: people in marginalized relationships invest significantly less in those relationships than people in socially accepted ones.6PubMed. Marginalized relationships: the impact of social disapproval on romantic relationship commitment
There is an interesting twist, though. Despite investing less, people in marginalized relationships were actually more committed than their counterparts in accepted relationships. The researchers found that this compensation appeared to work through reduced perception of alternatives. In other words, when your social circle disapproves of your relationship, you feel like you have fewer options, and that feeling of having nowhere else to go functions as a kind of glue. It keeps people together, but not necessarily because the relationship is good. It keeps them together because leaving would feel like admitting the social critics were right all along.
This dynamic creates a trap. The couple stays committed, but the commitment is partly fueled by defensiveness and a shrinking social world rather than by genuine satisfaction. Over time, that isolation can become self-reinforcing. Friends and family pull away, the couple becomes more dependent on each other, and the stakes of admitting the relationship is not working grow higher with each passing year.
What Therapy Can and Cannot Do
Couples therapy designed specifically for affair recovery does exist, and it can help with some of the damage, though the results are more modest than people hope. A small study testing an integrative treatment for couples recovering from an affair found that the majority of couples were less emotionally distressed at the end of treatment, and the injured partners reported greater forgiveness.7PubMed. An integrative intervention for promoting recovery from extramarital affairs That sounds encouraging, but this was a study of only six couples who all completed treatment, which is a small and self-selected group.
A larger randomized trial of 89 couples painted a more nuanced picture. Therapy produced significant improvements in anxiety for both partners, but depression scores only improved for the unfaithful partner. More critically, the treatment did not produce sufficient improvement in relationship satisfaction for both partners.8PubMed. Therapy for couples after an affair: a randomized-controlled trial The researchers themselves noted that future work needs to figure out how to help couples achieve more sustained improvement in how they actually feel about the relationship, not just how they manage the crisis.
This distinction matters. Therapy can help people feel less anxious, process trauma, and develop better communication. What it cannot reliably do is manufacture the satisfaction and security that a relationship needs to thrive. For couples who formed through an affair and are trying to build something lasting, therapy addresses the aftermath but does not erase the structural disadvantages the relationship carries.
The Odds for the Original Marriage
Some readers searching this topic are not asking about the new relationship formed through an affair. They want to know whether the original marriage can survive. The numbers are sobering. In a clinical study of 62 cases of extramarital relationships, about a third of the marriages ended in divorce that therapists attributed to the infidelity. Roughly 44% of the marriages were preserved but in an overall negative atmosphere. Another small fraction were technically intact but emotionally empty or still in doubt. Only about 15% of the marriages were reported as both intact and characterized by genuine improvement and growth, and half of those involved one-time affairs rather than ongoing ones.9PubMed Central. The impact of extramarital relationships on the continuation of marriages
Those numbers suggest that while recovery is possible, it is uncommon, and meaningful recovery where the marriage is actually better afterward is rarer still. The couples who do rebuild successfully tend to be ones where the affair was a single incident rather than an extended relationship, and where both partners were willing to do sustained, uncomfortable work over months or years.
Why the Pattern Repeats
One of the more uncomfortable findings in this research area is that infidelity and mate poaching tend to recur. The evolutionary framework for understanding this is called the “mate switching hypothesis,” which proposes that humans have psychological mechanisms designed to evaluate opportunities to leave one partner for another. These mechanisms respond to things like unexpected costs from a current partner, changes in either partner’s desirability, and the arrival of an appealing new option.10Personality and Individual Differences. The mate switching hypothesis In this framework, affairs are not random failures of willpower. They are the output of a system that is always, at some level, monitoring whether the current relationship is the best available option.
Individual differences matter here. Research reviews have found that infidelity and mate poaching are influenced by personality traits including a preference for novel experiences, antisocial tendencies, sexual permissiveness, and attachment orientation.11The Oxford Handbook of Evolutionary Psychology and Romantic Relationships. Mate Poaching, Infidelity, and Mate Switching These traits do not disappear when someone enters a new relationship. A person who scored high on novelty-seeking and sexual permissiveness before the affair still scores high afterward. The new relationship may feel novel now, but novelty fades, and the same traits that drove the original affair become risk factors for the next one.
This is the core challenge for affair-born relationships. The very qualities that made the affair happen, a willingness to pursue attraction outside commitment, comfort with secrecy, a tendency to compare partners, are qualities that threaten the new relationship just as much as they threatened the old one. Some people genuinely change after the upheaval of an affair, developing more self-awareness and stronger boundaries. But the research suggests that for many, the pattern is more stable than they realize.
Attachment Styles and Who Is Most Vulnerable
Not everyone who has an affair shares the same psychological profile. Attachment style, the way a person habitually relates to romantic partners, plays a role in who is most likely to become involved in infidelity. Research linking attachment patterns to marital infidelity has found that insecure attachment, whether anxious or avoidant, is associated with higher rates of extramarital involvement.12PubMed Central. The interplay of attachment styles and marital infidelity: A systematic review and meta-analysis
Anxiously attached people tend to seek reassurance through intensity and closeness, which can make the early stages of an affair feel deeply fulfilling. Avoidantly attached people tend to pull away from emotional intimacy, making them more likely to keep relationships at arm’s length and to compartmentalize an affair as separate from their primary bond. In either case, the attachment pattern does not resolve itself just because the affair partner becomes the primary partner. The anxiously attached person will eventually start seeking reassurance in the new relationship just as desperately, and the avoidant person will eventually pull back in the same ways.
Understanding your own attachment style is one of the few things that might genuinely shift the odds. People who recognize their patterns and work on them, often in individual therapy rather than just couples therapy, have a better chance of building something stable regardless of how the relationship started. But this requires a level of self-honesty that the cognitive dissonance surrounding an affair actively works against.
When Affair Relationships Do Survive
It would be dishonest to claim that no relationship born from an affair ever works. Some do, and the people in them are often eager to point out that their situation is the exception. The question is what distinguishes the exceptions from the majority that do not last or do not thrive.
Based on the available research, a few factors seem to matter. Relationships where the affair was not part of a broader pattern of infidelity fare better than those where serial poaching is involved. Relationships where both partners eventually acknowledge the harm caused, rather than minimizing or rewriting history, tend to have a stronger foundation for honesty going forward. And relationships where both partners have social support, even if that support was slow to develop, avoid the isolation trap that undermines marginalized couples.
The honest assessment is that affair-born relationships can survive, but “survive” and “thrive” are different standards. Staying together is achievable for many couples, especially when the costs of separating are high, children are involved, or the social network has reshuffled around the new partnership. Building a relationship that is genuinely satisfying, trusting, and secure is a harder task, and the research suggests it requires confronting exactly the dynamics that most people in these situations would prefer to avoid. The affair itself has to become a topic that can be discussed without defensiveness, which means both people have to stop needing the affair to have been a good decision and start dealing with it as something that happened, caused harm, and now requires honest reckoning.