Why men stay in long term affairs (and why they rarely choose)

It has been two years, or five, or eleven, and nothing has happened.

Maybe you're the wife who just found out how long this has been going on, and you're doing the math on every anniversary.

Maybe you're the other woman, and you've heard "after the holidays" for the third year.

Maybe you're the man himself, typing this at a red light, wondering how a temporary thing became a second life.

Or maybe the part you can't get past is simple. If he loves her, why hasn't he left? If he loves you, why hasn't he stopped?

Most explanations pick a villain. He's a narcissist. He's a coward. He just wants sex. He's trapped by a loveless marriage.

Those stories are satisfying, and they miss the central fact. A long affair isn't a failure to decide. It's what a decision looks like when someone refuses to pay for it.

He hasn't failed to choose. He's chosen not to choose, again, every week.

Below: the 7 reasons men stay in long term affairs, why the arrangement can hold for years, what happens to marriages that grow out of affairs, and a 14-day plan for whichever seat you're in.

One thing to be straight about. This site doesn't help anyone keep an affair going or hide one. This page is about understanding it, so you can stop waiting for it to resolve on its own.

Why men stay in long term affairs: the arrangement pays them twice

Here is the direct answer. There's no single reason, and these patterns come from clinical observation more than hard data. A long affair usually lasts because of some mix of these.

1. He gets both worlds – Home gives him history, children and stability. The affair gives him desire, attention and escape. Ending either one means a real loss.
2. He's never had to test it – The affair has no bills, no in-laws, no flu. It stays in its best light because it's never asked to do anything hard.
3. He has compartmentalized – He keeps each life in its own room and rarely lets them meet, which spares him from feeling the full conflict.
4. Leaving would cost too much – Children, money, property, faith, family, reputation. These pressures are real, even when they're also excuses. If you're the one weighing it, read what to know before leaving your marriage for an affair partner.
5. He feels seen there – Some men describe a version of themselves in the affair that they lost at home. He's less attached to her than to who he gets to be around her.
6. The guilt keeps him in place – Guilt toward his wife stops him from leaving. Guilt toward the other woman stops him from ending it. Each one blocks the only exits.
7. Nobody has forced the question – As long as both women wait, staying costs him nothing today. Avoidance is rewarded every single week.

Notice what isn't on the list: a clean verdict on who he really loves.

Here is the difference between what he says and what the arrangement does.

These are possibilities, not diagnoses. You'd need his real behavior over time to know which applies.

The research on long affairs is thin, and the numbers online are mostly invented

You'll see figures about how few affairs last or how few become marriages.

Ignore them. Most of them trace back to nothing, and nobody has run a good census of hidden relationships. The honest answer is that there's no reliable percentage.

There is relevant research, though, and it explains the mechanism better than any statistic could.

Compartmentalization is a documented strategy. In interviews with women who had marital affairs, researchers found four ways participants limited the conflict between their actions and values, and compartmentalization was one. It was a small study of women, not men, but the mechanism isn't specific to one gender.

Staying is often about constraint. Commitment isn't only about wanting. Galena Rhoades, Scott Stanley and Howard Markman studied a national sample of 1,184 unmarried adults and found dedication and several kinds of constraint each predicted whether relationships lasted. Constraints included social pressure and material ties. That study wasn't about affairs, but it helps here: a man can stay in a marriage for reasons that have little to do with how he feels about it, and then look elsewhere for the feelings.

Secrecy doesn't keep a relationship good. It keeps it going while it gets worse. Research from Keith Campbell and Craig Foster found virtually nothing good in the long term about secret romantic relationships. Secrecy may add allure early, and that allure degraded quickly in their studies. They surveyed undergraduate students, not married people, so read that as a hint. Still, it undercuts the idea that a long-running secret is a sign of a great love.

Think of it as The Two-Budget Problem

Here's a way of seeing the whole thing.

Picture a company that keeps two sets of books. One records the real costs: the mortgage, the arguments, the school run. The other records only the income: the excitement, the admiration, the feeling of being wanted.

Of course the second business looks healthier. It has no expenses.

Call this The Two-Budget Problem.

A long affair runs on the second set of books. Every hard, boring cost of a shared life gets charged to the marriage. Every good feeling gets credited to the affair. Over the years, the comparison feels like evidence. I'm so much happier with her. He isn't lying, and he isn't measuring anything real either.

This is why the affair so rarely survives contact with an audit.

And it's why an affair can last for a decade and still not be a relationship anyone has tried yet.

If you can't tell whether what's going on at home is a bad stretch or a second set of books, the free assessment can help you see what has changed. It can't prove anything, and it isn't meant to.

What happens to marriages that come from affairs

You'll want a number here. There isn't a good one.

Some relationships that began as affairs do last. Some are happy. Anyone who tells you all of them fail is selling you comfort.

But here's what changes the day it comes out of hiding.

The books merge. Now she's the one who sees him sick, broke and tired. The role that was never asked to carry anything has to carry everything.

The history comes along. Children, an ex-spouse, a community that knows how this began. You don't start clean. You start with baggage nobody has unpacked.

Trust has a known weakness. You both know exactly how this person behaves when a relationship gets hard. A longitudinal study by Kayla Knopp and colleagues found that people who reported infidelity in one relationship were three times more likely to report it in their next. That's a real risk factor, though it's not a sentence. Here's more on whether a serial cheater can change.

But what if ours is different?

It might be. Everyone in this position thinks so, and some are right. The only way to find out is to take the relationship into daylight and see what it does there. A promise can't tell you that.

How to get out of the holding pattern in 14 days

So what do you actually do with this?

Here is The 14-Day Audit. The steps differ by seat, but the principle is the same: stop waiting for his decision and start making yours.

If you're his wife

Days 1–3: Stabilize. Eat, sleep, tell one safe person. A long deception is a major shock, and you don't owe anyone a decision this week. Expect to replay years of memories. This guide to surviving infidelity can help you get through the first stretch.

Days 4–10: Get the facts you need, not all of them. Ask for how long, whether it's over, and whether you need a medical test. If you still have doubts about the pattern at home, the assessment can give shape to what's changed.

Days 11–14: Set the terms. Contact must end fully, not fade. Couples therapy begins, or you see someone alone. If he won't do either, you've got your answer about what he's offering. These posts on staying after cheating and when to walk away will help you weigh it.

If you're the other woman

Days 1–3: Write down the timeline. Every promise and every date it was supposed to happen. Seeing it on paper is different from remembering it.

Days 4–10: Name your deadline. Not an ultimatum to win him. A date for yourself, after which you stop waiting.

"I'm not asking you to leave. I'm telling you I won't be here after March."

Days 11–14: Mean it. Speak to a therapist, who can help you with the grief as well. Going back can feel urgent for a biological reason: a small brain imaging study led by Helen Fisher linked romantic rejection to brain areas involved in motivation, reward and addiction cravings.

If you're him

Days 1–3: Stop calling it undecided. You've made a decision every week for years. Own what it has cost two people.

Days 4–10: See a therapist alone. Not to feel better. To work out what you've been avoiding, and to stop using either woman as your solution.

Days 11–14: Make the real choice. End it cleanly, or end the marriage honestly. Here's how to end an affair if that's the road. Michael Slepian's research on secrets found that the harm comes less from the hiding than from living with the secret, thinking about it again and again. You already know how that feels.

For all three seats: if anyone has made threats, is controlling you, or has you scared about what happens when this comes out, call the National Domestic Violence Hotline at 1-800-799-7233.

Waiting is the only thing keeping it alive

You came here to understand him.

That's fair. But understanding can become one more way to stay in the holding pattern, one more month of reading into his silences.

An affair like this survives on everyone's patience. It needs the wife not to know, or not to act. It needs the other woman to believe in next year. It needs him to believe that time will settle what he won't.

Time won't settle it.

The moment one person stops waiting, the whole structure has to tell the truth about what it is.

Sources

• Permission-Giving and Marital Infidelity, Jeanfreau, Herring and Jurich, University of Southern Mississippi
• Should I Stay or Should I Go? Predicting Dating Relationship Stability from Four Aspects of Commitment, PMC
• Secret romantic relationships research by Campbell and Foster, ScienceDaily
• Once a Cheater, Always a Cheater? Serial Infidelity Across Subsequent Relationships, Knopp and colleagues, PMC
• Study finds romantic rejection stimulates areas of brain involved in motivation, reward and addiction, Rutgers University
• Why the Secrets You Keep Are Hurting You, Michael Slepian, Scientific American
• National Domestic Violence Hotline