
1. He/She is overly critical of everything you do. He/She seems annoyed or offended by the way you do even the smallest daily tasks (even if those some things never seemed to bother him/her before).
This might seem unrelated to infidelity, but criticism is one of the most common signs. As a spouse starts pulling away from the marriage, he/she wants to justify the affair. He/she falsely justifies it by making you, the faithful spouse, seem like a terrible person. Meanwhile, he/she is most likely fixating on his/her cheating partner and seeing this other person as “perfect” by comparison. Of course, all of this is a delusion fueled by lust and selfishness, but the faithful spouse becomes verbally mistreated in the process.
#2 often happens simultaneously with #1. #2 is also a common trait among Sociopaths and Narcissists…