If you get accused of something you know never happened it means your wife is fishing and baiting for you to react. It’s actually not uncommon for the manipulator to bait with using an additional person as a witness even when this person doesn’t exist.
Narcissists like to create drama and will at times make contact baiting for a response and drama. They get bored and like to create drama.
They are void and are always looking for a high. I have seen a lot of this in individuals that have addiction issues. Their game is “I use”. In other words “ I use drugs, bars, and insert self in drama or create drama for a HIGH and to feel relevant.”
She is also trying to guilt trip you so you give in.
This is why the less contact you have with her the better.