Leaving your marriage for an affair partner (read this first)

You are thinking about leaving your marriage for the person you are having an affair with, and you have told nobody.

Maybe you have already pictured the apartment, the Sunday mornings, and the life where you don't have to check your phone in the bathroom.

Maybe you feel more alive with this person than you have felt in ten years.

Maybe you look at your spouse across the kitchen and feel only tired, then guilty for being tired.

Or maybe the affair partner has started asking when, and your stomach drops every time.

You keep arguing with yourself. Part of you says this is finally your real life. Another part says this is the worst mistake you will ever make.

Most advice on this does one of two things. It tells you that affairs never last, so go home. Or it tells you that you only get one life, so follow your heart.

Both skip the part that matters, because neither one can see your marriage or your affair.

You don't have one decision to make. You have two, and the affair is hiding that from you.

Below: what research shows about leaving a marriage for an affair partner, why the affair feels so much better than real life, the 3 ways people get this wrong, and a 90-day plan for deciding with a clear head.

One thing to be straight about. This site doesn't help anyone hide an affair, and nothing here is a guide to running one for longer. The plan below has you step out of the secrecy, because you can't make a clear decision from inside it.

Leaving your marriage for an affair partner rarely goes the way the affair promises

Here is the direct answer. Some people leave a marriage for an affair partner and build a lasting life with that person. On average, though, the odds are harder than the affair makes them feel.

Here's what the evidence shows:

• Most affairs don't become relationships – In one analysis of people who admitted cheating, summarized in Psychology Today, about 1 in 10 affairs became a committed relationship. It's one self-report study, so read it as a rough signal.
• Most marriages don't end over the affair either – In that same analysis, about 1 in 5 primary relationships ended because of it. Everyone in a love triangle tends to believe a bigger ending is coming than usually does.
• Relationships that begin this way report more strain – A study in the Journal of Relationships Research compared relationships formed by taking someone from a partner with relationships that didn't overlap. The first group rated satisfaction, commitment and trust lower, and jealousy higher, and they reported more infidelity.
• Commitment can slide after the switch – Joshua Foster's team tracked 138 people over nine weeks. Those who had been lured from a previous partner started out less committed and less satisfied, and they reported falling commitment and satisfaction as the study went on. A later sample found the same weaker commitment but not the decline.

Those are group averages, and Foster's first sample averaged just 20 years old, so this isn't a study of long marriages. It says nothing certain about you or the person you love.

They do mean one thing clearly: "we'll be different" isn't a plan. It's what most people in that data probably believed too.

Why the affair feels like the real thing

The feeling isn't fake. That's what makes this difficult.

You may truly feel seen, wanted and awake. Those are real experiences, and most advice insults you by calling them a fantasy.

But look at the conditions that produce them.

An affair has no mortgage. It has no stomach flu, no in-laws, no argument about whose turn it was. You meet when you both want to be there, usually dressed for it. The danger itself adds charge, because every meeting has the feel of something stolen.

Meanwhile, your marriage has been carrying all of the weight that the affair gets to skip.

You are comparing someone's highlights with a person who has seen you at your lowest, and who you have stopped trying with. Some of that distance came from the affair itself, because the energy you used to bring home has been going elsewhere.

Then again, your marriage may have real problems. The research doesn't say it's all an illusion. When researchers asked divorced people why they split, lack of commitment, infidelity and constant conflict topped the list. Lots of marriages truly end, and some of them should.

Dylan Selterman's University of Maryland study adds a useful complication. He found that people cheat for a range of reasons, many of which don't reflect the health of the relationship.

That means the affair isn't proof that your marriage is dead. It also isn't proof that it's alive.

It tells you very little about your marriage, and that's the trouble with using it as evidence. A cleaner start is a plain look at what has changed between you and your spouse, and the assessment can help you put that into words.

The Greenhouse Effect: why an affair can't tell you if love will survive

Gardeners know this one. A plant grown in a greenhouse can look stronger than anything in the yard, with warm air, no wind, and no frost. Then you move it outside in the wrong week, and it collapses.

It wasn't fake. It had just never met the weather.

Call this The Greenhouse Effect.

An affair is a greenhouse. The secrecy keeps the air warm, and the marriage takes the storms. The relationship inside can be genuine and still untested.

So the question isn't "is this love?"

The question is "what happens to this when the weather gets in?"

The weather means your children's faces. It means your friends picking a side. It means their anger at something you did in week three, and your fear about who they are texting when they go quiet. Remember, you each know exactly how good the other is at hiding things.

That last one matters more than people expect. Kayla Knopp's University of Denver team followed 484 adults across two relationships and found that those who cheated in the first were three times more likely to report it in the next. It's a risk, not a sentence. Still, it means the trust question doesn't go away once you are together in the open. It often gets louder.

But what if we really are the exception?

You might be. Some couples are, and the way to find out is to take the plant outside slowly, on purpose, instead of hoping that spring will last forever.

There are 3 ways people get this wrong

The Leap – You leave in a rush of certainty, often after a fight or an ultimatum. You move out before your spouse knows the truth, and the affair partner suddenly has to be everything. A relationship that was built on a few hours a week gets a full-time job overnight.

The Slow Leak – You stay, keep the affair going, and tell yourself you are "figuring it out." Months become years. Everyone gets less of you, and the people who are waiting for you pay for your indecision. If this is you, read why men stay in long term affairs. The pattern isn't only about men.

The Trade – You treat this as a swap: one person out, one person in. You never ask what went wrong, what you did, and what you would bring with you. The new relationship gets the same you, and in two years, you may start to feel the same way again.

The fourth way is the slow and honest one. You separate the two decisions, and you make each of them in daylight.

How to decide in 90 days without blowing up your life twice

So what do you actually do with this?

Use The 90-Day Daylight Plan. It has one rule: the marriage decision and the affair partner decision get made separately, in that order.

Days 1 to 7: stop the clock

Stop making promises. Don't set dates, don't look at apartments together, and don't tell your affair partner what you'll do. Any promise made now is a promise made from the greenhouse.

Book an individual therapist this week. It's the single best thing on this list, because you need one room where you don't have to manage anyone's feelings. You can read about what therapy for a cheating spouse actually involves.

Take the relationship assessment too. It won't tell you what to do or prove anything. It will give you a cleaner picture of what has actually changed in your marriage, instead of what the affair has been telling you.

Days 8 to 30: take the affair off the table

Pause contact with the affair partner. Tell them clearly that you need to think, and that you can't do it in the middle of this. If you need help doing that, read how to end an affair.

Expect withdrawal, not relief. You may grieve. You may feel your marriage looks even worse for a while.

Note how the other person responds. Someone who can respect this pause is showing you something. So is someone who threatens you, floods your phone or tells you to prove your love.

If they threaten to tell your spouse, or if you start to feel unsafe with anyone involved, keep records and contact the National Domestic Violence Hotline at 1-800-799-7233.

Days 31 to 60: answer the marriage question on its own

Ask this and write the answer down: If this other person did not exist, would I still want to leave this marriage?

Then ask the harder one: Have I ever told my spouse what was really wrong, in words they could not misunderstand?

If the answers are yes and yes, your marriage may truly be over, and that decision stands on its own feet.

If you never actually tried, then consider whether you want to. Couples therapy can help. In a study of 145 couples dealing with infidelity, those couples started out more distressed than others, kept improving through therapy, and at follow-up could not be statistically distinguished from couples in therapy for other reasons. Whether, and how, to tell your spouse the truth is a conversation to have with your therapist before you have it at home. Our guide on divorce after infidelity can help you think it through.

Days 61 to 90: get the practical picture

Talk to a family lawyer in your state before any big move. Every US state recognizes no-fault divorce, but some states also let courts weigh adultery in property, alimony or custody decisions. This article isn't legal advice, so ask directly how your situation is treated where you live.

If you have kids, plan their experience of this first and yours second.

Only after the marriage decision is settled do you turn to the other person. If you leave, leave for your own reasons, and give the new relationship a slow start in the open: real time, real friends, real weather.

Here's a script for your affair partner:

"I've made a decision about my marriage, and I made it separately from you. I'd like to find out what we are without the secret. That means going slowly, and neither of us being anyone's rescue."

If you leave, you take yourself with you

Here's the part that no affair can warn you about.

The person you are with your affair partner feels like a new person. You are lighter, funnier and more honest in certain ways.

But that person was built in a place where nothing was ever asked of you.

So the real question was never who to choose. It was what you want your life to be, and whether you are willing to tell the truth to get it.

Answer that one first, and the choice between two people gets much smaller.

Leave for something, not for someone.

Sources

• The 8 reasons why people cheat, Psychology Today
• Why find my own when I can take yours? The quality of relationships that arise from successful mate poaching, Journal of Relationships Research
• The psychology of "mate poaching", British Psychological Society
• Reasons for divorce and recollections of premarital intervention, Scott and colleagues, PMC
• Why do people cheat? UMD research identifies 8 motivating factors, University of Maryland
• Once a Cheater, Always a Cheater? Serial Infidelity Across Subsequent Relationships, Knopp and colleagues, PMC
• Outcomes of couples with infidelity in a community-based sample of couple therapy (Atkins et al., Journal of Family Psychology), PubMed
• No-fault divorce, Legal Information Institute, Cornell Law School
• Adultery, Legal Information Institute, Cornell Law School
• National Domestic Violence Hotline