Your partner used to be someone you could read. Now they defend the affair partner, rewrite the history of your marriage, and look at you with a flatness that feels like a stranger wearing a familiar face. You may have heard a name for this: affair fog. And underneath it, another word: limerence.
Here is the short answer. Affair fog is real in the sense that people in affairs often enter a state of intense idealisation, secrecy, and distorted judgment that looks very different from who they were before. Limerence is the name often given to that state: an intense, intrusive preoccupation with another person. Dorothy Tennov, who coined the term in Love and Limerence (1979), described it as driven above all by hope plus uncertainty — the hope of reciprocation kept alive by not knowing. In an affair, novelty and fantasy feed that uncertainty, but they are the context around limerence, not Tennov's definition of it. It can feel like love from the inside and look like obsession from the outside. It usually fades — but there is no fixed deadline, and it rarely lifts while secret contact continues. What you do while it lasts matters more than winning an argument about whether it is "real love." And it does not excuse the affair: understanding a state is not the same as accepting the behaviour that came with it.
What affair fog looks like day to day
Fog is not a medical diagnosis. It is a description betrayed partners keep reaching for because it fits what they see. The signs tend to cluster: idealising the affair partner as uniquely understanding or "the only one who gets me"; rewriting the marriage in darker colours ("I was never happy," "We were already over"); defending the affair partner and treating ordinary questions as attacks; flatness at home, where warmth and curiosity disappear while energy flows toward the affair; sudden urgency about divorce or permanent decisions; and secrecy as a reflex, where even small things get hidden.
That distinction matters: a name is not an explanation. Adrian J. Blow and Kelley Hartnett's reviews of the infidelity literature examined how the field defines its terms, and the lesson applies here — a descriptive label like "fog" describes what you are seeing; it does not, on its own, explain why it is happening or when it will lift.
None of this proves your partner is a bad person at their core. It shows that their judgment is operating inside a very biased environment — secrecy, novelty, and selective attention. Mira Kirshenbaum, in When Good People Have Affairs, describes people who live, psychologically, in two relationships at once: the marriage, with all its ordinary reality, and the affair, with its concentrated intensity.
What limerence is — and how it differs from love
Limerence, as Tennov described it, is an intense, involuntary preoccupation with another person: intrusive thoughts, a craving for reciprocation, euphoria when the other person responds, and despair when they do not. It is driven less by who the other person actually is than by hope plus uncertainty — the reward of attention that might come, and might not.
Esther Perel, in The State of Affairs, explores how affairs draw power from desire, secrecy, and identity: the affair can feel like a discovery of a truer self, precisely because it happens outside the routines and responsibilities of the marriage. That feeling can be genuine. It does not make the comparison fair.
The comparison itself is the tell. Limerence is built on partial knowledge: an affair partner is usually encountered in a concentrated slice — attention, desire, novelty, escape — while a spouse is encountered in full reality. Love, as it is usually meant in a long-term relationship, is built on full knowledge and survives contact with the unglamorous parts of a person. Limerence needs uncertainty to stay intense — "Will they text? Do they really want me?" — while love can tolerate certainty. Limerence idealises; love sees clearly and can hold affection and honest criticism at the same time.
None of this means the feelings inside limerence are fake. They are usually very real to the person experiencing them. The problem is that they are being used as evidence — "I feel this strongly, so it must be true love, so my marriage must have been wrong" — while the person is standing inside the most biased conditions possible for judging that question.
Why the certainty feels so convincing
The most disorienting part is often the certainty in your partner's voice when they say things you know are not true — that the marriage was always empty, that the affair partner is their soulmate. Part of the answer is secrecy itself. Ellyn Bader and Peter Pearson, in Tell Me No Lies, write about honesty, secrecy, and differentiation: what is kept secret is protected from ordinary challenge, so the story inside it never gets tested against daylight.
There is also the simple fact that stopping now would feel like loss — losing a person, and losing access to a version of oneself that felt alive. That grief is real, and it is one reason the fog can look like love. For a closer look at the machinery behind this — novelty, uncertainty, reward, and the way fantasy outcompetes reality — read Why Affairs Feel So Powerful: The Science of Infidelity.
How long does affair fog last — and what prolongs it?
This is the question almost every betrayed partner asks, and it deserves an honest answer: there is no reliable timetable, and anyone who gives you one is guessing.
What can be said with confidence is that fog is a state, not a permanent change of character, and states change when their conditions change. Adrian J. Blow's synthesis of infidelity research makes the same point in research terms: affairs are shaped by contributing factors, circumstances, and consequences, and by the treatment considerations that follow — which means the conditions around the affair matter more than any label put on it. Fog lasts as long as the conditions feeding it last. When secret contact continues and the affair partner remains available and idealised, the fog has everything it needs to go on. When contact genuinely ends, secrecy is replaced by transparency, and the person is forced — by reality, not by argument — to see the affair partner and the marriage in full, the fog usually begins to thin. That thinning is rarely a straight line.
Tennov, working from interviews, estimated that a limerent episode often lasted roughly eighteen months to three years. That was an estimate about limerence in general, drawn from interviews — not a timetable for fog lifting once contact ends, and it should not be used as one.
Two cautions matter. First, do not treat any timeline as a promise: building your decisions around a date someone else invented will only set you up for a second betrayal when the date passes. Second, do not assume that time alone does the work. Time passing while contact continues is not the same as time passing after contact has ended. The clock that matters starts when the secrecy stops, not when the affair was discovered.
The things that keep the fog alive are worth naming, because they are also the things you can ask to change: continued contact of any kind, including "just checking in" or contact "for closure"; secrecy, where part of the affair stays hidden; uncertainty, where your partner keeps both options open; and being argued with — paradoxically, trying to argue your partner out of the fog often strengthens it, because the argument becomes evidence that you are the obstacle and the affair partner is the refuge. Katherine M. Hertlein and Fred P. Piercy's work on internet infidelity and digital boundaries is directly relevant here: contact does not have to be in person to keep the fog alive — messages, social media, and "just checking in" online all count as contact, and clear digital boundaries are part of ending it. Willard F. Harley Jr. and Jennifer Harley Chalmers, in Surviving an Affair, are direct on this point: recovery cannot properly begin while the affair continues in any form, because the conditions that sustain the fog are still in place.
What you can do while it lasts
You cannot think your partner out of limerence, or love them out of it by being more attractive or more accommodating. What you can do is protect yourself, set clear conditions, and stop spending energy on what does not work. Talal H. Alsaleem's Systematic Affair Recovery Therapy (SART) follows a similar order: its seven milestones move from disclosure and understanding the affair, through processing the emotional injuries, to making informed decisions about the relationship and building a recovery plan. That sequence is a useful guide for you too — steady yourself first, understand what you are dealing with, and do not rush the decisions.
Steady yourself first. Anne Bercht, founder of Beyond Affairs, emphasises emotional stabilisation in the early aftermath of discovery — how hard it is to think clearly while emotional safety is gone, and why practical guidance and steady support matter before any bigger decisions. Barbara Steffens and Marsha Means, in Your Sexually Addicted Spouse, describe the trauma responses that follow sexual betrayal: hypervigilance, intrusive thoughts, and a body that stays on alert. None of that is weakness. Before you try to fix the marriage, get sleep, eat, lean on one or two trusted people, and consider individual support from a therapist experienced with infidelity.
Stop trying to argue the fog away. Presenting evidence or proving the marriage was good will not work while your partner is inside the state. Save the detailed conversations for a time when contact has ended and your partner can actually hear you. Michele Weiner-Davis, in Healing from Infidelity, emphasises crisis stabilisation and practical behaviour change over endless analysis in the early weeks: change what can be changed now, and revisit the bigger questions when the crisis has steadied.
Ask for what is concrete, not for a feeling. You cannot demand that your partner stop feeling something. You can ask for observable behaviour: no contact with the affair partner, full transparency about messages and whereabouts, a complete and honest account of what happened, and a willingness to attend support or therapy. Lee Williams's seven-A framework for repair starts in the same place, with apology, acknowledging the hurt, accountability, and atonement — taking responsibility, ending the affair, and restoring honesty before trust can be rebuilt. Judge behaviour rather than promises.
Set boundaries you can keep. A boundary is not an ultimatum designed to control your partner's feelings. It is a clear statement of what you will do if a condition is not met. "I need contact with the affair partner to end, and I need to see that it has ended" is a boundary. "You must stop loving them" is not something you can enforce. Choose boundaries that protect your safety and dignity, state them once, clearly, and follow through — including digital boundaries, so that "no contact" covers messages and social media as well as meeting in person.
Set a review point instead of deciding everything now. Discernment Counseling, developed by William J. Doherty and Steven M. Harris, is a short, structured process — typically one to five sessions — for couples where one or both partners are unsure about the future. Its purpose is clarity, not reconciliation: by the end, a couple chooses among three paths — staying as things are, committing to six months of couples therapy with divorce off the table, or separating. Separately from that model, you can set your own review point as a personal practice: agree on a date to revisit what has actually changed, with clear conditions in the meantime, rather than trying to decide stay or leave in the middle of the crisis.
What not to do
Do not compete with the affair partner: you are being compared as a whole person against a curated slice, a contest you cannot win. Do not become the detective full-time — some checking is understandable early on, but endless monitoring exhausts you and changes nothing. Do not make permanent decisions in the hottest moment; you are allowed to say, "I will not decide that today." And do not use the fog as a weapon in an argument — "You are just in limerence" — it will be heard as dismissal.
If you are the one in the fog
This section is for the unfaithful partner reading this and recognising themselves. You may feel certain that what you feel is love. It is worth asking: Do I know this person in their ordinary life, or mostly in the concentrated moments we share? Am I keeping secrets that would change how I see this in daylight? Have I rewritten my marriage's history to make the affair feel inevitable? If all contact ended for three months, what would I expect to feel? If the answer frightens you, that is information.
Bader and Pearson's point about honesty and differentiation applies here too: secrecy lets a story survive that daylight would challenge. Caroline Madden, in Blindsided by His Betrayal and Fool Me Once, writes about how to recognise authentic remorse and genuine behavioural change — which is why waiting for a feeling to pass is not a plan: repair shows in consistent behaviour, not in declarations. Harley and Chalmers make the practical side plain: rebuilding trust means ending the affair, preventing further betrayal, and creating the conditions that support long-term commitment.
If you are in the fog, the most honest step you can take is to create the conditions where you can think clearly: end contact, stop the secrecy, tell the truth in full, and give yourself time away from the affair partner before deciding the future of your marriage. You cannot evaluate two relationships fairly while you are standing inside one of them.
How to tell when it is lifting
Fog does not lift in a single dramatic moment. It lifts in observable changes, and behaviour is a more reliable guide than declarations. Look for curiosity returning, defensiveness dropping, transparency offered rather than extracted, realistic talk about the affair partner as idealisation softens, patience with your questions, and consistent behaviour over weeks rather than days. Caroline Madden's test of genuine behavioural change points in the same direction: what returns first is not a declaration, but the ordinary, steady behaviours of connection. Alsaleem's SART likewise treats rebuilding as a staged process of milestones, not a single moment of insight. If you see these changes sustained over time, that is real progress. If you see only promises without them, the fog is probably still in charge.
Fog explains. It does not excuse.
This is the part the conversation around affair fog often gets wrong. Understanding limerence can bring relief — finally, there is language for what happened to the person you married. But language is not absolution. Your partner made choices: to keep secrets, to cross boundaries, to lie, to keep going after the harm was visible. Fog may explain why those choices felt easy from the inside. It does not remove responsibility for them.
That distinction matters for both partners. For the betrayed partner, it means you do not have to choose between compassion and accountability. For the unfaithful partner, it means the work is not to wait for the feelings to pass — it is to own what happened and do the repair, whether or not the fog has fully lifted.
For a fuller picture of the patterns behind the "different person" you are seeing, read How Could They Do This? Inside the Mind of an Affair?
One manageable next step
You did not cause the fog, and you cannot argue it away. But you are not powerless while it lasts. The next step is small and specific: steady yourself, name the conditions you need, set a review point, and watch behaviour rather than promises. If your partner is willing to end contact, be transparent, and do the repair work, there is something to build on. If they are not, that is also information.
If it would help to talk through your situation privately, RenuuAI is a private AI recovery coach that can help you map one manageable next step — stabilising yourself, preparing a conversation, or working through what to ask for — with support between appointments, on your own schedule. It is not therapy, and it will not decide stay or leave for you.
Sources
- Dorothy Tennov — Love and Limerence: The Experience of Being in Love (1979) (book citation, no URL)
- Adrian J. Blow and Kelley Hartnett — Infidelity in Committed Relationships I and II (model/research citation, no URL)
- Mira Kirshenbaum — When Good People Have Affairs: Inside the Hearts and Minds of People in Two Relationships (book citation, no URL)
- Esther Perel — The State of Affairs: Rethinking Infidelity (book citation, no URL)
- Ellyn Bader and Peter Pearson — Tell Me No Lies: How to Face the Truth and Build a Loving Marriage (book citation, no URL)
- Katherine M. Hertlein and Fred P. Piercy — Research on internet infidelity and digital boundaries (model/research citation, no URL)
- Willard F. Harley Jr. and Jennifer Harley Chalmers — Surviving an Affair (book citation, no URL)
- Talal H. Alsaleem — Systematic Affair Recovery Therapy (SART) (model citation, no URL)
- Anne Bercht — Beyond Affairs (model citation, no URL)
- Barbara Steffens and Marsha Means — Your Sexually Addicted Spouse: How Partners Can Cope and Heal (book citation, no URL)
- Michele Weiner-Davis — Healing from Infidelity: The Divorce Busting Guide to Rebuilding Your Marriage After an Affair (book citation, no URL)
- Lee Williams — Seven-A framework for relational repair (model citation, no URL)
- William J. Doherty and Steven M. Harris — Discernment Counseling (model citation, no URL)
- Caroline Madden — Blindsided by His Betrayal and Fool Me Once (book citation, no URL)