Cheaters sometimes accuse faithful spouses of their own (hidden) behavior.
A common one I have heard is the cheater accusing the faithful spouse of cheating! This happens while they are actually the ones cheating.
It is crazy!
As this post suggests, a cheater might accuse the faithful spouse of duping their family and close friends while the cheater herself is actually doing this.
I wish this stuff was pure fiction. Sadly, it is not. Cheaters do all sorts of these things.
They turn around and blame the other partner for their own behaviors. It is as if they see the world as they are. They cannot help but assume everyone behaves in the same treacherous way.
It is so sad. But it is also toxic and another reason to separate oneself from someone so consumed with such delusions.