https://damelegal.com/blog/signs-spouse-having-affair/
The signs of cheating look different in every relationship, but there are multiple items you can look for to determine if your spouse is having an affair.

https://www.relate.org.uk/relationship-help/help-relationships/affairs/ive-found-out-my-partner-having-affair-what-should-i-do
I've found out my partner is having an affair, what should I do? - Give yourself some time. - Talk to your partner - Ask your partner to tell you the truth, however painful.

https://www.mariemurphyphd.com/post/non-judgmental-advice-for-people-having-an-affair-part-i
The single most common reason clients seek me out is that they're having an affair and want help figuring out what to do. And when I explain this to someone ...