Someone Married Said "I Love You": Can You Believe It?
No one can check from the outside whether a married person's "I love you" is true, and research gives you no reason to call it a lie. What it does show is that feeling love and leaving a marriage run on separate tracks. The better evidence is what this person does in the weeks after saying it.
Maybe it came as a voice note while you were standing in the queue at the pharmacy, or it was said quickly in a car park, just before the other car pulled away. Since then the sentence has followed you into meetings and into conversations with people who have no idea. The person who said it is married, or in a committed relationship, and goes back to that life after every time you meet. The words sounded like a beginning, and so far nothing in your days has changed.
On Quora the question appears almost word for word: "Can I trust a married man when he says that he loves me?" It is asked about married women too: "A married woman says she loves me but can't leave her husband now." I answer it here with what research can support, and I will tell you where the research runs out.
Can you believe a married person who says "I love you"?
Fisher, Aron and Brown (2006, Philosophical Transactions of the Royal Society B) describe three systems: sex drive, romantic attraction and attachment, which they call largely distinct yet interrelated. That attraction and attachment can point at two different people is my reading of their model. The paper is a review built on small brain-imaging studies and did not look at affairs.
A survey of Ashley Madison users, people who signed up specifically to find an affair, fits that reading (Selterman, Joel and Dale, 2023, Archives of Sexual Behavior). Low satisfaction, love or commitment at home was not a major driver of their affairs. But this group is self-selected and does not speak for every affair.
How do you know if they really mean it?
The figure comes from a meta-analysis by Bond and DePaulo (2006, Personality and Social Psychology Review) of people judging statements in real time, without training or aids. People also tended to see the person in front of them as honest. None of the studies involved declarations of love, but they show how little one moment reveals.
A sentence can be sincere and still promise nothing, because "I love you" describes a feeling, not a plan. Instead of trying to catch a lie, write down over a few weeks what has changed since they said it.
Why do they stay married if they love you?
Le and Agnew (2003, Personal Relationships) tested Caryl Rusbult's model across 52 studies with 11,582 participants. Satisfaction, alternatives and investments together explained nearly two thirds of how committed people felt, and that commitment predicted whether the relationship later broke up. These are correlations, so they show associations rather than causes.
For you this cuts both ways. That this person stays does not disprove what they said, since someone can love you and still be tied to a life built over years. It also means you are only one of three factors in that equation.
Will they leave their partner for you?
Selterman, Garcia and Tsapelas (2021, Journal of Sex & Marital Therapy) surveyed 495 US undergraduates and online participants about their affairs. When the motive lay in the primary relationship, such as anger at a partner or a lack of love, the affairs lasted longer, included more public dates and more often ended the primary relationship.
Affairs that grew out of stress or intoxication were shorter and less often led to disclosure or a breakup. These are self-reports about groups, so they cannot forecast your situation. One question is still worth taking from them: is what you have becoming more visible over time, or does it stay where nobody sees it?
Why can't you stop thinking about what they said?
Whitchurch, Wilson and Gilbert (2011, Psychological Science) showed college women the Facebook profiles of male students. Those unsure how much the men liked them thought about them most and found them most attractive. Montoya and colleagues (2015, Psychologia) could not reproduce the rise in attraction. What held was a stronger wish to get in touch and meet.
So the loop in your head says nothing about how big this love is, in either direction. It tells you the question hangs on a sentence only the other person can make good on, which is why testing it again and again gets you nowhere. You get further with questions only you can answer.
What writing can do with a sentence you cannot check
Whether the declaration is true is out of your hands. How long you want to live like this is not, and that part fits on paper. A few lines a day are enough:
- What did this person say or do today?
- What has changed since the declaration, and what has not?
- How did I feel about both?
If you miss a day, you simply carry on.
To start without buying anything, the free Check-in from Journals by Simone shows you in four questions where you stand.
Frequently asked questions
Does a married person mean it when they say "I love you"?
The sentence alone will not tell you, whether it comes from a married man or a married woman. People spot lies only slightly better than chance (Bond and DePaulo, 2006). What happens in the weeks afterwards tells you more.
Can you love two people at the same time?
The model of Fisher, Aron and Brown (2006) allows for it. Romantic attraction and long-term attachment count there as largely separate systems, so someone can be attached at home and still have fallen in love with you.
How long should I wait for them to decide?
Research offers no deadline, and I found no sound figure for how often people actually leave. You can answer the other half of the question: how long you want to live like this, and what would show you that something is moving.
Does writing help when I can't stop thinking about them?
It can, but the effect is small and shows up with a delay (Guo, 2023). Writing separates what was said from what happened afterwards, and a few lines a day work well without turning it into a duty. If the thoughts disrupt your sleep or your days for weeks, talking to a counsellor or therapist is a sensible step. If thinking about this person barely stops, limerence may explain what is going on.
Sources
- Bond, C.F. and DePaulo, B.M. (2006). Accuracy of deception judgments. Personality and Social Psychology Review, 10(3), 214–234. doi.org/10.1207/s15327957pspr1003_2, PubMed 16859438 (retrieved 14 October 2026)
- Fisher, H.E., Aron, A. and Brown, L.L. (2006). Romantic love: a mammalian brain system for mate choice. Philosophical Transactions of the Royal Society B, 361(1476), 2173–2186. doi.org/10.1098/rstb.2006.1938, PubMed 17118931 (retrieved 14 October 2026)
- Guo, L. (2023). The delayed, durable effect of expressive writing on depression, anxiety and stress: A meta-analytic review of studies with long-term follow-ups. British Journal of Clinical Psychology, 62(1), 272–297. doi.org/10.1111/bjc.12408, PubMed 36536513 (retrieved 14 October 2026)
- Le, B. and Agnew, C.R. (2003). Commitment and its theorized determinants: A meta-analysis of the Investment Model. Personal Relationships, 10(1), 37–57. doi.org/10.1111/1475-6811.00035 (retrieved 14 October 2026)
- Montoya, R.M., Faiella, C.M., Lynch, B.P., Thomas, S. and DeLuca, H.K. (2015). Further exploring the relation between uncertainty and attraction. Psychologia, 58(2), 84–97. doi.org/10.2117/psysoc.2015.84 (retrieved 14 October 2026)
- Selterman, D., Garcia, J.R. and Tsapelas, I. (2021). What do people do, say, and feel when they have affairs? Associations between extradyadic infidelity motives with behavioral, emotional, and sexual outcomes. Journal of Sex & Marital Therapy, 47(3), 238–252. doi.org/10.1080/0092623X.2020.1856987, PubMed 33377428 (retrieved 14 October 2026)
- Selterman, D., Joel, S. and Dale, V. (2023). No remorse: Sexual infidelity is not clearly linked with relationship satisfaction or well-being in Ashley Madison users. Archives of Sexual Behavior, 52(6), 2561–2573. doi.org/10.1007/s10508-023-02573-y, PubMed 37010618 (retrieved 14 October 2026)
- Whitchurch, E.R., Wilson, T.D. and Gilbert, D.T. (2011). "He loves me, he loves me not ...": Uncertainty can increase romantic attraction. Psychological Science, 22(2), 172–175. doi.org/10.1177/0956797610393745, PubMed 21169522 (retrieved 14 October 2026)
Simone Pleifer, MSc
Simone Pleifer, MSc, is the founder of Journals by Simone and the creator of the Emotional Clarity Journey system. She holds an MSc in Nutritional Science and has 14 years of experience in pharmaceutical clinical research. Her work bridges scientific rigour and emotional depth for people navigating secret love, situationships, and unspoken feelings. She is currently developing a supplement line to complement the ECJ system.
About Simone