Signs Your Partner is Cheating: The Full List (Science-Based)

signs of cheating

Can you always spot the signs that your partner is cheating? Well, not always.

But if you are observant and keep your antennas up, chances are you can catch a cheating partner more times than not.

After this post, which leverages scientific literature and data, you will know what signs to look for.

emotional affair

Signs of Cheating

There are many possible signs of cheating, but you should look for clusters and patterns rather than relying on a single piece of evidence -unless you catch them with their pants down, then you don’t need anything more :)-.

Here are some key clusters:

#1. Changes in Behavior

The central tenet here is that an affair will change your partner’s behavior.

This is not always true, of course, but it’s a fairly reliable sign of a change in your partner’s life.

Here is what is more likely to change in a cheating partner”

  • More critical and unforgiving toward you
  • Doesn’t talk as much
  • Unusually apologetic
  • Excludes partners from social events
  • Goes out by himself
  • Refusal to be accountable for their whereabouts

#2. Has Less Time For You

The cheating partner needs to meet the affair partner.

And that time needs to come from somewhere.
That means, less time for you or for activities he used to perform.

These are some common signs related to time:

  • More work trips
  • Longer hours at work
  • Less family involvement
  • Misses social gatherings with a spouse or excludes her
  • More weekend commitments

#3. Renewed Passion for Life

Sometimes life and relationships can grow stale.
An affair can bring a whirlwind of renewed passion and lust for life.

A cheating spouse might:

  • Start going to the gym
  • Buy new clothes/underwear / sexy or stylish garments
  • Interest in new activities
  • Abandon activities shared with the partner
  • New diet and efforts to lose weight
  • Happier, more confident (at least when not dealing with the spouse)

Here’s an example of the dynamic I’m talking about from the movie “Election”.

The man in the video has a boring relationship with his wife and the affair gives him wings:

Note: to fix these affairs, you need to fix your relationship.

#4. Changes In Behavior Towards Money

Unfaithful partners might need more expenditures for their side partners.

This means:

  • More privacy around money
  • Balance not adding up
  • A different pattern of withdrawals
  • More money spent on lifestyle and beauty

#5. Explanations Are Too Fuzzy or Too Elaborated

What happens if you confront them?

Well, the cheater will most likely not admit to cheating.
Not right away, at least.

Instead, he/she will come up with some explanations.
And to explain away their changes cheaters might be either overly detailed, or they might use blanket rules.

The blanket rules sound like these:

  • New project
  • I’m stressed out for work
  • So many more demands with the new responsibility

You can expect lots of details instead from more shrewd individuals.

Changes in Details

It’s an important sign if they were previously sharing stories about work, or a specific person, and now it doesn’t happen anymore.

#6. More Demand for Privacy

Cheaters need more personal space to carry on communication with the affair partner.

An increased search for privacy or for personal space is a good indicator of betrayal.

Here are some examples:

  • Locks the door
  • Goes outside to speak on the phone
  • Clears the browsing history
  • Puts a password on his phone (and hides it from you)
  • Stashes his phone away if you’re looking
  • Gets nervous if you get close while he’s at the computer

a cheating sign

#7. Random Changes

So far we have signs that clearly go in one direction: either increase or decrease.

However, depending on personalities and relationships, some other indicators will just change, and we can’t make a blanket rule on whether they increase or decrease, improve or worsen.

Change is the only good indicator for:

  • Sex frequency
  • Passion
  • Sex experimentation
  • Warmth and kindness
  • Irritability, meannesscriticism, and contempt
  • Frequency of arguments
  • Frequency of “I love you”

Stay away from sources that say an increase or decrease of any of the above is a strong sign of cheating.
That’s just not true.
Different people will react differently when it comes to sex, kindness, and, yes, even the frequency of “I love you”.


For example, a partner feeling guilty might become nicer to you to overcompensate.

The same for a partner who wants to preserve both relationships: he might be nicer out of fear and subconscious prevention.
A partner who doesn’t want to be in the relationship anymore and who is emotionally involved in the affair can instead become irritable and pick more fights than he used to.


A partner with an awakened sex libido will want to have sex more often, while monogamous partners might completely avoid sex with you.

Women also have a higher tendency to withdraw from sex with their husbands when they engage in affairs.
On average, though the changes when it comes to sex are not exaggerated. The rule of thumb is that there is no significant impact on marital sex as long as the affair stays secret.

Strongest Signs of Cheating

Some signs carry a very big weight in assessing whether your partner is having an affair or not.

These are the most obvious signs of cheating:

  • Proposes you should see other people
  • Doesn’t want monogamy anymore
  • Actively avoids talking about certain people or groups
  • Doesn’t answer when you ask if they are cheating
  • Accidentally calls you by someone else’s name
  • Turns down dates more often
  • Friends report you they’ve seen them with someone else
  • Forgets anniversaries
  • A sexually transmitted disease you didn’t have (doh!)

We will now focus on the different psychological personalities of a cheater.

Understanding where your partner fits will give you strong cues on what to look for.

Monogamous Types

The personality of the monogamous type only allows him to have one partner at a time, and he cannot compartmentalize two different lives (Glass & Write 1997).

When the monogamous type cheats, the affair takes over.
It becomes the prime relationship and they struggle in keeping up a facade of love and kindness in the official relationship.
The monogamous types are more likely to withdraw from sex and affection in the relationship because they feel unfaithful to the partner with whom they are now emotionally bonded.

The monogamous type:

  • Withdraws emotionally
  • Stop or reduces sex
  • Decreases affection (kisses, hugs)
  • Forgets anniversaries and special dates
  • Cares less
  • Sometimes shows high irritability
  • No more saying “I Love you”

Note: the monogamous type is not a 0 to 1 switch, but it’s on a scale.
So you can find the signs of the monogamous type, but more or less pronounced, depending on where your partner sits on the scale of monogamous/polyamorous.

Rationalizing The Affair Away

Monogamous cheaters -that name makes little sense I know :)- are also more likely to rewrite their relationship history because of cognitive dissonance (Festinger, 1957).

They are more likely to tell themselves -and you- that they are unhappy, that their partner is not good enough, or even that they never loved their partner.

Don’t necessarily believe that: they need it to appease their cognitive dissonance (commitment and consistency principle, Cialdini).

They Want to Get Caught

The monogamous type wants to end the dual life which is causing cognitive dissonance.
That’s why when confronted, they usually cannot muster the strength to deny or build a castle of lies.
They are more likely to passively confirm. Or to actively volunteer information.

Marshall in How I Met Your Mother is a typical example of a monogamous type:

Indeed if you fail to confront them they might either get caught on purpose, start leaving more and more obvious signs or they might end one of the two relationships.
And when you confront them, they are more likely to admit it (example from A Walk On the Moon).

Player Types

The player types don’t seek outside relationships with emotional involvement but will seek cheating opportunities nonetheless.

Players will have little or no signs of affairs because they don’t often have emotional affairs but go for short-term flings.

Signs of Players

They will:

  • Go out by themselves more often
  • Check out other women (sometimes without hiding)
  • Have a long history of playing the field
  • Show love to women (plural!)
  • Make jokes about them and other women
  • Insist on taking trips on their own

Also, read:

Cheater Types

Some inveterate cheaters actively seek to keep simultaneous relationships as a mating strategy.

These are the guys who keep long-standing affairs but, at the same time, also want to keep the relationship with you, and they want you to stay emotionally attached as well.
Exactly: these are the slimmest.
So if they start an affair they are more likely to unconsciously overcompensate with more affection.

Signs of Cheaters

Some cheaters may not increase their affection, but some do:

  • Say “I love you” more often
  • Show more caring and affection
  • Are unusually happy to be together

Compartimentalizer Types

Some cheaters are very, very good at lying and compartmentalizing lives.

They are so good because it’s not even “lying” for them, it’s just having two separate realities.
They have no intention to abandon the relationship and, as a matter of fact, often take extra steps to keep their relationship safe.

Emotionally and sexually they show little changes and they often lead lives that allow them to easily cover their tracks (ie.: business trips, offshore commitments, nomadic lifestyle, etc.).
That’s why it’s very difficult to sniff out the cheating signs of a compartmentalized.

Sometimes the affair partner doesn’t even know they were in a relationship.

The movie Up In The Air is a great example of a compartmentalizer:

Tips to Uncover Betrayals

And of course, you don’t have to limit yourself to passively analyzing information but you can actively look for the signs of cheating.

Here are some examples:

  • Check mileage on the odometer
  • Count condoms (or viagra pills)
  • Check credit card reports
  • Hire a detective
  • Check their phone while they sleep
  • Voice-activated voice recorder (this is the highest rated on Amazon)

You can place it in their car or under the bed when you’re away.
But if you don’t find any signs, you might also want to consider that you’re over-worrying.

Gender of Cheaters

If we look at Google, the searches “what are the signs your husband is cheating” or “signs your husband is cheating on you” are more popular than the equivalent for wives.
This is an indicator that women worry more.

And indeed data suggest that men still cheat a bit more frequently than women.
However, in the last decades, women have been catching up.

Historically men cheated primarily for sex and women primarily for emotional connection.
Men have been catching up to women here and cheating with emotional involvement has been growing for men.

If you want to understand the unpleasant phenomenon of cheating a bit more also check the following


As we have seen you can’t always and reliably tell if someone’s cheating.

It depends a lot on their personality and psychological makeup.
Stay away from articles like “what every man does when he’s cheating” because they are simply untrue.

This article gave you a good overview of what are some of the most common signs of cheating and of how the different personalities behave during affairs.

This guide references the work of infidelity experts such as Shirley Glass, author of “Not Just Friends“, empirical research (such as Cues to Infidelity, Personality & Social Psychology Bulletin, 1997), evolutionary psychology sources (such as The Moral Animal) and the author’s knowledge acquired through personal experiences and delving into psychology and relationship literature.  

1 thought on “Signs Your Partner is Cheating: The Full List (Science-Based)”

  1. When a woman loves you,she loves for real and its always quite obvious. with my partner it was love at first sight and everything was going well until she started acting up. Restraining her mobile from my reach which made me more suspicious.
    A professional helped me find out the truth and i was totally perplexed. I found out that she was not over her ex and they still see each other whenever i travel for contract jobs overseas. Regardless of the fact that i pay the bills and if i loose my life today she dies rich. I’m happy to be living alone with my son far away from a cheat. Nobody deserves a liar as a partner.

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