Why People Cheat – Even if They’re in a Loving, Committed Relationship

There’s no betrayal quite as hurtful as infidelity. Discovering your spouse or partner has cheated on you can create feelings of distrust, anger, and confusion — especially if you feel your relationship is a happy one. But in fact, it’s not only unstable relationships that are rocked by affairs. Often, loving, committed marriages and partnerships suffer the effects of infidelity, too.

The question cheated-upon partners inevitably ask, of course, is “Why?” When a relationship seems to be going well, it can be difficult to point to reasons one partner would stray. Experts say a variety of factors can lead to affairs.

“I believe that anyone is capable of engaging in infidelity within a relationship,” says licensed therapist Kendra Capalbo, who has a couples counseling practice based in Cambridge, Massachusetts. Sometimes, this is due to life circumstances like stress, lack of sexual satisfaction, or even boredom. But other times, it’s a matter of small frustrations adding up. “Unaddressed issues in the relationship and small voids often lead individuals to start filling those gaps with someone else,” she says.

Cheating in a monogamous relationship is never a solution to problems. But here are seven reasons therapists say it happens.

1. Lack of Sexual Satisfaction

A sex life that’s lacking in some way is a classic reason partners stray. And research shows it’s not just a stereotype. In a study published in 2021 in The Journal of Sex Research, people who had affairs listed lack of relationship satisfaction (specifically sexual satisfaction) among the top reasons they were unfaithful. Higher relationship satisfaction predicted a lower likelihood of infidelity, while lower satisfaction increased the likelihood of cheating.

According to Los Angeles–based sex and relationship therapist Tammy Nelson, PhD, it’s critical to communicate with your partner about your sex life to prevent affairs driven by desire. “Communicating about sex and sharing fantasies and what we really want from our partner can be scary, and the risk of rejection, embarrassment, and shame can prevent us from opening up,” she says. “But there’s a risk of avoiding these tough conversations, too.”

2. Boredom

It’s not always something as foundational as sexual dissatisfaction that leads partners to cheat. Often, people are simply looking for novelty. “Boredom can drive committed spouses to seek excitement outside of the relationship,” Capalbo says. “Our brains excel at rationalizing gradual boundary crossings, often triggered by boredom.”

Still, marital malaise is rarely the only factor behind unfaithfulness. “I don't believe boredom itself is the sole threat to marital fidelity. Instead, it is often accompanied by taking our partners for granted and feeling like we are being taken for granted in return,” Capalbo says. She encourages partners to keep the spark alive by scheduling regular date nights (the more exciting, the better), traveling together, and trying new things in the bedroom.

3. Opportunity

Among happy partners, unfaithfulness sometimes boils down to being in the wrong place at the wrong time. “Most infidelity, regardless of the health of the marriage or committed partnership, happens because of opportunity,” Dr. Nelson says. “Certainly, there are cases where one partner intentionally seeks out an affair … but there are also professions that are likely to have more organic opportunities for cheating.” If a spouse travels for work, for example, they may often be in situations where trysts are easy and available.

The rise of social media and online connection has also created more opportunity for infidelity. “The internet has facilitated the initiation of affairs in a way that was not as prevalent before,” says Capalbo, citing the possibility of reconnecting with old flames or new friends online. “I have heard clients describe emotional affairs primarily occurring online through direct messaging or texts. The ability to ‘turn it off’ at any point can contribute to the dangerous rationalization process.”

4. Feeling Neglected

We all crave affection and attention. If we don’t receive it from our partner, we may seek it elsewhere. A study published in 2020 in the Journal of Sex and Marital Therapy found that feeling neglected was one of eight top variables in the development of affairs. Perhaps even more significant: The more people felt neglected, the greater intimacy they reported with their extramarital partners. That was expressed in ways like public displays of affection and a higher likelihood of saying “I love you” to the person they were cheating with, and staying in affairs longer.

Nelson says showing affection is a two-way street in marriage. She encourages showing your partner your interest by expressing desire for them or letting them know you miss them when they’re gone. And when you feel unloved or devalued, speak up! “Be specific with your request. Is it time, attention, affection, or sex that you are longing for?”

5. Anger

Arguments are totally normal in long-term relationships, and healthy partners are no strangers to anger. But left unchecked, this emotion can drive some people to unfaithfulness. In an older study in the Journal of Social and Personal Relationships, anger was among the top four motivations underlying affairs.

But perhaps predictably, cheating out of anger is only likely to lead to more anger. A recent review of infidelity research showed that anger was one of the most common emotional responses from partners who had been cheated on.

6. Over-Imbibing

Alcohol is well known for reducing our inhibitions. Overdoing it at a bar or a party can make us do things we regret. “When people drink, they tend to become more flirtatious, making it easier to cross the subtle boundaries and rationalize their actions,” Capalbo says. Intoxication could lead otherwise satisfied spouses to make (or accept) an inappropriate advance. “It's important to understand that drinking doesn't always lead to an affair, but it is an additional factor that requires honest self-assessment and awareness.”

7. Low Self-Esteem

Poor self-image is a motivator for all sorts of negative behaviors, including extramarital affairs. “In some cases, affairs can arise from a desire for self-esteem or an ego boost, particularly in individuals who struggle with low self-esteem as a recurring theme,” says Capalbo. “People whose sense of self-worth is heavily dependent on external validation are at a higher risk.”

If you know your partner struggles in this area, you can help them by “speaking” their love languages. This might look like offering words of encouragement, providing plenty of physical affection, or performing loving acts of service. (And, of course, they can always seek the help of a trained therapist to get to the root of low self-esteem.)

On the other hand, if you’re the partner who requires extra validation, Capalbo encourages staying aware of how this affects your propensity to stray. “Self-awareness allows you to establish firmer boundaries if you receive attention from someone outside the relationship, preventing yourself from being further tempted by the allure of that attention.”