Let’s talk about what cheaters can’t hide — the guaranteed signs of cheating.
Whether you’re seeing lipstick on collars or catching weird phone habits, it’s time to stop wondering and worrying.
Table of Contents
How to Tell if Someone Is Cheating: Common Signs
Cheaters tend to follow the same playbook. The signs aren’t always as obvious as coming home to your spouse’s secretary in your bed though.
In fact, any single sign might have an innocent explanation. But when the red flags start stacking up? That’s when your Spidey senses should be tingling.
1. Sudden secrecy
They used to scroll through TikTok with their head in your lap. Now they’re angling the phone away from you on the other side of the sofa. If they start hiding their phone, changing passwords, turning it face down, or getting jumpy every time you walk by, that’s shady af.
They might also guard their daily schedule, suddenly not wanting to share details about where they’re going or who they’re meeting. You notice they’re working late more often or coming up with vague explanations for their absences. They might also get unusually private with their belongings — keeping their wallet, bags, or even car off-limits.
When you ask for an explanation, they flip the script faster than a Netflix series gets canceled. Suddenly, you’re “insecure” or “controlling.”
(Read about actual controlling partners here.)
This shift in behavior isn’t random — it often means they’re keeping something from you. In the absence of other signs, let’s hope they’re just planning a surprise trip to Fiji for your anniversary.
2. Changes in routine
Those “quick drinks with coworkers” are stretching longer than a Peter Jackson film, and somehow every client meeting just has to happen after hours. And don’t get me started on the sudden and mysterious gym sessions. Since when was your partner such a fitness fanatic?
These unexplained absences aren’t just coincidences; they’re often a cover for something else. If they used to have a predictable schedule but are now constantly busy or hard to reach, it’s worth paying attention.
A sudden increase in vague excuses or disappearing without notice can point to a deeper issue — one that might just involve someone else.
3. Emotional distancing
Once they used to blow up your phone with memes and random thoughts all day. Now getting them to text back is like expecting a straight answer from a Magic 8 Ball. The person who used to ask about your day now gives you the same energy as a bored teenager at a family dinner.
Instead of being present, they seem distracted or even cold. This emotional checkout often happens when someone’s investing their emotional energy elsewhere.
Experts call this emotional infidelity. Relationship researchers Guitar et al. explain emotional infidelity as “when a person in a relationship creates an emotional distance by spending an excessive amount of time with, or thinks about, another person outside of the relationship, to the point that the other partner becomes ignored.”[1]
4. Unexplained expenses
Depending on the level your relationship is at, you might notice changes in your partner’s spending habits, especially if you have a joint account. I’m talking random coffee shops in parts of town they never visit, late-night Uber rides that make zero sense, or “business lunches” that cost way more than a sandwich should.
These expenses often come with vague explanations, if any at all.
They might brush it off as “work stuff” or “just something for a friend.” But hidden expenses like this can reveal a lot about their activities — and sometimes, they’re exactly the clue you need to confirm your suspicions.
5. Increased grooming or appearance changes
When your partner suddenly starts putting extra effort into their appearance without a clear reason, it could be a red flag. Look, there’s nothing wrong with a glow-up, but when it comes out of nowhere, with no clear explanation? That’s when your radar should start beeping.
Maybe they’re hitting the gym more often, updating their wardrobe, or taking extra time to get ready.
If they’ve never cared much about their looks before, this sudden change might mean they’re trying to impress someone else. Small changes like wearing cologne daily or dressing up for “casual” events can be telling.
6. Lack of intimacy
If your partner stops showing physical affection or if bedroom activity drops noticeably (or they’re suddenly bringing home moves you haven’t seen before), it might mean they’re getting it elsewhere.
They may even start criticizing your appearance or habits out of the blue — comments they never made before.
This shift in behavior can mean that they’re looking for reasons to distance themselves emotionally and physically. When a previously close connection feels cold or strained, it’s worth considering whether someone else is taking the attention and energy they once shared with you.
7. Being too defensive or too nice
When a partner gets extra defensive about harmless questions or, out of nowhere, starts showering you with gifts and attention, it’s often a red flag.
Defensiveness over little things usually points to guilt, as though they’re trying to hide something. On the flip side, they might go into “nice” overdrive — compliments, surprise gifts, or sudden affection — to keep you distracted. This push-pull behavior is a common tactic for people who feel guilty, and it’s often used to throw off suspicion.
Research suggests that “people experiencing guilt can alternate between irritability and efforts to make things up to their partner.”[2] If you feel something’s off, trust your gut feelings; these reactions don’t happen for no reason.
8. Unexplained phone behavior
When a partner’s phone suddenly goes on lockdown — silent mode, facedown, or with notifications hidden — it’s hard not to raise an eyebrow. Sneaky, right?
Phones are personal, but if they act overly protective, something could be up. Deleted messages, new contacts, or even a dating app you’ve never seen before are big red flags. What’s even sketchier is when they start doing that weird jump-and-grab move every time their phone pings.
Look, most people value privacy, but a sudden shift in phone habits or digital footprint can hint at secrets they’re trying to keep. If this sounds familiar, trust your gut — these behaviors often mean that something’s going on behind the scenes.
9. Accusations of cheating
When they start playing detective about your behavior, it’s usually because they’re the ones with something to hide. Psychologists call this “projection,” but I call it the “I know you are, but what am I?” defense.
According to clinical psychologist Dr. Ramani Durvasula, this behavior is common among partners trying to deflect guilt or shame by accusing others of the very things they’re guilty of. If these baseless paranoid accusations start piling up, it’s time to take a closer look.[3]
10. Showering immediately upon getting home
A sudden need to “freshen up” the moment they walk through the door can be a way to wash away the evidence. Maybe it’s the smell of someone else’s perfume or just an attempt to cleanse themselves of the ick of being a cheater.
If they don’t want to hug or talk before they hit the bathroom, that’s a bit suspect, too. Sure, some people have sweaty jobs and they need to clean up before they do anything else, but if this is out of character, it’s worth paying attention.
It’s the change in routine that’s telling — especially if they used to greet you first but now seem desperate to get “clean” right away.
11. Unfamiliar scents, lipstick marks, or injuries
Speaking of ick, a cheating partner might come home smelling like someone else’s perfume or sporting a lipstick mark that clearly isn’t yours. It sounds like an old Hollywood cliché, but clichés exist for a reason.
Don’t ignore any “mystery injuries” they can’t quite explain, like scratches on their neck or bruises they brush off with, “Oh, I don’t know where that came from.” Uh-huh. Doing the deed in the janitor’s closet.
If these “oops” marks keep showing up, it’s worth asking some pointed questions. Scent, makeup smudges, and unexplained marks aren’t foolproof signs alone, but put together? They definitely suggest someone else has been in close range.
Uncommon Signs of Cheating
When it comes to infidelity, most people think of the obvious signs, like secretive phone behavior or emotional distance. However, there are also uncommon signs of cheating that can slip under the radar.
Recognizing these can help you figure out how to know if your partner is cheating.
1. Different sleep patterns
Your partner used to be the world’s biggest sleep enthusiast. Now they’re suddenly wide awake at 2 a.m., tapping away on their phone like a sleep-deprived teenager. Or maybe they’re hitting the gym at the crack of dawn when they used to sleep in until noon on the weekends.
Occasional bouts of insomnia are not uncommon among adults. In fact, about 30% of the adult population in the US deals with symptoms of insomnia.[4] But if the person who used to need 10 hours a night is now getting by on 5 — and they’re not complaining about it — something’s up. This change could suggest they’re hiding something, like sneaking around or talking to someone else during those odd hours.
2. Unusual interests
If your partner suddenly develops new hobbies or interests that don’t match their usual passions, it might be a red flag. Often when a partner adopts a new hobby, it’s not out of the blue. You’re there when they discover it, they mention it in passing, and all this happens before the fiery enthusiasm takes hold.
If they start obsessively pursuing activities they’ve never shown interest in before — even hated before — it could raise some questions. Your partner who once hated pickleball like the Capulets hate the Montagues is now ordering his own special paddle and rambling about “dinking.” You’ve offered to get into it too but they say you “wouldn’t like it.”
So, who exactly got them to start liking pickleball?
3. Changes in group dynamics
While there’s nothing wrong with having new friends, there’s cause for alarm if your partner suddenly starts spending way more time with a new friend group you’ve never even heard of.
Maybe they’re ditching their old crew to hang with these “new friends” all the time. Or they’re making plans with people you’ve never met, and the excuses just don’t add up. Pay attention if they talk about these new friends often or seem secretive about their outings.
This sign hits even closer to home if it’s your joint friend group whose dynamic shifts. If your partner and another member of your friend group start acting shifty around each other, take note.
4. Frequent unexplained absences
If your partner’s whereabouts don’t quite add up, that’s a red flag you can’t ignore. Look for vague excuses about “late nights at the office” or ambiguous “plans.”
Maybe they’re leaving for “work trips” that don’t quite align with their actual job duties. Or they disappear for hours on end, only to give you the ol’ “my phone died” excuse when they finally show back up.
While everyone gets busy sometimes, consistent and unexplained absences — especially if they don’t invite you or share much about their time away — might suggest they’re not being completely honest.
5. Overly interested in your phone use and social exposure
If your partner suddenly seems way too curious about who you’re texting or what you’re doing online, it can be a red flag, especially if there’s an air of nervousness about them. If they’re frantically trying to find out if you’ve talked to Sandra or Paul lately, that’s weird.
All this nosing in on your activity could mean your partner is worried you’re onto him and his wandering ways or that someone saw them with their paramour and you found out about it — or will soon.
On the other hand, when they start questioning you more than usual about your phone or social media, it could just mean they’re projecting their own behavior. Like I mentioned earlier, a partner feeling guilty or hiding something will assume you’re doing the same and try to shift the focus to your actions instead.
6. A newfound interest in spirituality or self-improvement
When they suddenly dive into spirituality or self-help, it might look like they’re just on a personal growth journey, but it could actually be a way to justify straying or to pull back emotionally.
They might start spouting mantras about “finding themselves” or “needing space to grow,” which sounds nice until you realize it’s making them more distant. So, while they’re busy “aligning their chakras” or “embracing new vibes,” keep an eye out.
Sometimes, this sort of soul-searching is not all about self-love. We all know about Jonah Hill’s expedition into therapy lingo and how he disguised emotional abuse as setting the boundaries he heard about in therapy. Don’t let your partner use this new age self-discovery lingo to cover up their transgressions.
7. A sudden desire to spend more time with extended family
As alibis go, this one is pretty good. We usually encourage our partners to stay close with friends and family, so we’re unlikely to call this out. But if they suddenly seem overly invested in “catching up” with people they usually try to avoid, consider it a warning.
Maybe they’re heading out for “family game night” way more than before or reconnecting with a distant cousin. This sudden social butterfly act boils down to shadiness. Who are they really with? You’ve never even heard of this “cousin.”
What Counts as Cheating?
Cheating isn’t just about physical intimacy — it can take many different forms that feel just as hurtful and damaging. Each type of cheating breaks trust in its own way, often causing deep emotional pain.
1. Physical cheating
Physical cheating is one of the most straightforward types of infidelity. It involves engaging in physical intimacy with someone outside your relationship. When most people think of cheating, this is usually what comes to mind.
Here are some common examples of physical cheating:
- Kissing
- Engaging in foreplay or intercourse
- Spending the night
- Dancing suggestively
- Participating in intimate acts, like touching or fondling
- Cuddling
2. Emotional cheating
Emotional cheating happens when one partner forms a deep emotional connection with someone outside the relationship.
It’s like having a backup spouse — you know, that person they text about their bad day before they tell you or the “friend” who knows more about your relationship problems than you do.
Here are some common signs of emotional cheating:
- Confiding in someone else about personal issues
- Spending significant time texting or chatting online
- Sharing intimate details that you don’t share with your partner
- Prioritizing someone else’s feelings over your partner’s
- Developing a strong bond that replaces your emotional connection with your partner
3. Virtual cheating
In today’s digital age, infidelity has taken on a new form: virtual cheating. This can include flirting, sexting, or having romantic or sexual chats through social media, dating apps, or gaming platforms.
Many people may not realize that these online behaviors can be just as hurtful as physical cheating.
Here are some common signs of virtual cheating:
- Flirting in private messages
- Sending suggestive pictures or texts
- Engaging in erotic conversations with someone else
- Using dating apps while in a relationship
- Hiding online activity or passwords
4. Micro-cheating
Micro-cheating is one of the most common types of infidelity. It’s those small actions that may seem harmless on their own but can suggest a wandering interest.
Here are some more examples of micro-cheating:
- Flirting with someone at work
- Texting an ex regularly
- Going to strip clubs without telling your partner
- Having an active dating app profile
- Liking or commenting on romantic posts from others
5. Financial infidelity
Financial infidelity is a sneaky type of betrayal in relationships. It happens when one partner hides money matters or engages in secret spending.
This can really damage trust, especially if it affects shared finances or future plans. Being open about money is key to a healthy relationship. Here are some examples:
- Hiding credit card debt
- Making large purchases without telling your partner
- Opening secret bank accounts
- Borrowing money from friends without informing your partner
- Concealing income or bonuses
6. Object infidelity
This type of “cheating” happens when a partner becomes overly obsessed with something non-romantic, like work, hobbies, or even a pet. This obsession takes so much time and energy that it strains the primary relationship.
While it might not seem as harmful as physical cheating, it can lead to feelings of neglect and resentment and leave you feeling lonely. Here are some examples of object infidelity:
- Spending excessive hours at work
- Being constantly absorbed in video games
- Prioritizing a pet’s needs over the partner’s
- Joining clubs or groups and not including the partner
- Having a hobby that takes time away from quality relationship moments
7. Commemorative infidelity
Commemorative infidelity is a particularly hurtful form of betrayal. It happens when one partner, often feeling emotionally disconnected, engages in emotional or physical cheating without experiencing guilt.
They may even justify their actions, believing they deserve better. This type of infidelity can be especially damaging because it often involves a lack of empathy and remorse.
- Seeking comfort from someone else after a fight
- Engaging in flirtation without thinking twice
- Justifying a one-night stand as a “reward”
- Sharing intimate thoughts with someone outside the relationship
- Believing that emotional needs aren’t being met at home
When you’re in a relationship with a toxic person, they don’t see things the same way you do. To them, cheating as retribution makes perfect sense.
Closing Out the Guaranteed Signs of Cheating
While one or two of these signs don’t guarantee cheating, a cluster of them is a dead giveaway — if not to cheating, at least to the fact that your relationship is in trouble.
Ultimately, open communication is important — sometimes a tough conversation can reveal the truth, even if it’s not what you want to hear.
If you’re facing a situation like this, remember, you deserve to be in a healthy, loving relationship. Don’t be afraid to seek support from friends, family, or a therapist.
We have more articles that can help you with being in a relationship.
If you’re fed up with the shenanigans and you need help ending a relationship, check out the link.
FAQs
What is the biggest predictor of cheating?
The biggest predictor of cheating is often past behavior. If someone has cheated in the past, they are more likely to do it again. Other factors include relationship satisfaction, opportunity, and personality traits, such as impulsiveness and narcissism.
How do cheaters act when caught?
When caught, cheaters often react by denying everything, getting defensive, or blaming their partner. Some may try to lie their way out, while others might apologize and promise it won’t happen again. Reactions vary, but many cheaters will try to avoid the topic altogether.
How do you know if someone is more likely to cheat?
You know if someone is more likely to cheat by looking at their past behavior and relationship history. People who have cheated before, have a history of lying, or show signs of emotional distance and secrecy are more likely to cheat. Those who value excitement and avoid commitment may also be more likely to cheat.
How do I make sure someone is cheating?
To be sure someone is cheating, look for patterns of secretive behavior, like hiding their phone, changing routines, or growing distant. Having an honest conversation can sometimes reveal the truth. If you’re unsure, consider asking a therapist for advice.
What is the evidence of cheating?
Evidence of cheating can include physical proof, like finding intimate photos, videos, or messages on their phone or computer. Sometimes, it’s even catching them in the act or seeing them with someone else. These clear signs can confirm suspicions that something serious is going on outside the relationship.
References
1. Guitar, A. E., Geher, G., Kruger, D. J., Garcia, J. R., Fisher, M. L., & Fitzgerald, C. J. (2017). Defining and distinguishing sexual and emotional infidelity. Current Psychology, 36, 434–446.
https://doi.org/10.1007/s12144-016-9432-4
2. Baumeister, R. F., Stillwell, A. M., & Heatherton, T. F. (1994). Guilt: An interpersonal approach. Psychological Bulletin, 115(2), 243.
https://doi.org/10.1037/0033-2909.115.2.243
3. Durvasula, R. (2015). Should I stay or should I go: Surviving a relationship with a narcissist. Simon and Schuster.
https://books.google.co.ke/books?id=-XUfDAAAQBAJ&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false
4. Marshall, S. (2024). Sleep statistics and facts. National Council on Aging.
https://www.ncoa.org/adviser/sleep/sleep-statistics/
