Have you noticed that your partner has started staying late at work more often, and his phone is always on silent mode?
Don't rush to conclusions, but look at the details.
The first warning sign is a sudden change in daily routine. A study in the Journal of Social and Personal Relationships found that 73% of cheating partners start “staying late at the gym” or “going on spontaneous dates.”

These excuses seem innocent, but their frequency and vagueness are red flags. For example, if he used to go to football three times a week at 7 p.m., and now suddenly adds “extra training” at 9 p.m., it’s worth asking questions.
The second marker is avoiding eye contact. Dr. David Matsumoto, an expert on microexpressions, says that constricted pupils and increased blinking indicate an internal conflict between lying and guilt. But it’s important not to confuse this with fatigue or stress.
The third sign is exaggerated criticism. Cheaters often project a sense of guilt, accusing their partner of non-existent sins.
For example: "You've become too fat" - when they themselves flirt with a colleague. This is an attempt to justify their behavior, shifting responsibility to the victim.
Tip: Do a "spontaneity test." Offer to spend the day together unexpectedly—for example, show up to work with lunch. If your partner gets nervous, refuses, or comes up with absurd reasons ("We're having an emergency office disinfection today!"), that's a conversation starter.
Another method is to observe the reaction to jokes about cheating. Psychologists note that innocent people usually laugh or ignore them, while guilty people get angry or change the subject.
The fifth sign was proven by an experiment at Monash University: cheating partners are 89% more likely to use the pronouns “they/he/she” instead of “I” in conversations (“Everyone does it at work”). This is an attempt to distance themselves from their actions.
Another marker is the “oversharing effect,” if he suddenly starts talking about his day in detail without asking questions (“And then I went to Starbucks, got a cinnamon latte, talked to the barista about the weather...”).
This may be an attempt to create an alibi, so it's worth paying attention to the details. The more of them, the higher the probability that the story is made up.
Even 3-4 signs are not a death sentence. Start with an open dialogue: “I have noticed changes. Let’s discuss what is happening.” If your partner is ready to talk, there is a chance to save the relationship.
If not, remember: life doesn't end. According to statistics, 80% of people who have experienced betrayal find happier relationships within two years.