Cheaters are already living a lie. Therefore, if you address your suspicions in the form of an accusation, their natural reaction may be to extend that lie via denial and deflection.
Here are a few common examples of how a cheater is likely to react to your questions about their affair.
“It’s all in your head, you’re going crazy”
A cheater will attempt to flip the script, turning your accusation into an unwarranted exclamation of your paranoia. This is a simple way to deviate from the subject while making you feel guilty in the process.
“Why don’t you trust me?”
This is a clear example of shifting the blame in your direction. Rather than explain him/herself, your spouse attempts to turn your suspicions into an example that you haven’t completely bought into the relationship.
“I’m at work, how could I have the time?”
Workplace affairs are fairly common, whether it’s odd, long work hours, lunch breaks, fraudulent errands, or business trips. Cheaters always find the time to satisfy their addiction or craving. Also, note this is a detour, not a full denial.
“We’re just friends”
While it could be possible, if it’s true, they’ll have nothing to hide. The relationship should be out in the open, and you should have met/interacted with this platonic friend. If he/she is confiding in a platonic friend rather than you, there’s a reason.
“I’m not on dating websites, that’s spam or I was hacked”
The evidence lies in the browser history. Does he/she have an account or have they visited pages of other active members? A user may know how to hide their tracks, but he/she might not be that savvy or get lazy after a while.
Once a person has begun their path of deceit, he/she pile on the fabrication and deny any wrongdoing in the process. The best way to find the truth is to catch them in the act; otherwise, you could be playing a losing game that affects your well-being.
Enlisting the expertise of a licensed private investigator that utilizes video/photographic surveillance is your best bet at uncovering the truth.