This is my SIL in a nutshell (where she belongs). Read the whole article by Gail Meyers here.
“This is how a narcissist gossips without appearing to be slandering anyone. The narcissist may even be perceived as a concerned, caring person. For example, [the Narcissist]… expresses her great concern… about [The Target’s] fragile emotional state. In reality, [the Narcissist] is being abusive and [the Target] is responding to the abuse, but [the Narcissist] is using that response as proof of your instability.”
So in a very real sense, the narcissist uses your reactions of anger, frustration or outrage to their abuse, to cause you to look crazy to other people.