We'll have to agree to disagree.
Have you noticed this is a consistent line from your narcissistic person?
I was triggered a little by this earlier when someone used this line on me, as my ex loved this one.
She'd use in response to a disagreement over something that was not particularly complicated or subjective, just one that she could not justify but didn't want to admit it.
I under if it's about some complicated philosophical point with too many subjective aspects to get resolution on. Maybe for the Trolley Problem or something like that.
I remember asking things like, "But what IS the part that we disagree on?" It usually was something that she legit owed me an apology for. Something she was caught doing that went against an agreement we had or something.
I think it's a way of dodging responsibility while implying at the same time that she's taking a higher road.
Reminds me of another one she loved to use when an apology was obviously the proper response: "You always have some special way that you require me to say something." No, actually I can think of a bunch of different wordings you could use, I just suggested one that would suffice. You're totally at liberty to use a different one as long as it contains some ownership. "Well, we'll just have to agree to disagree."😅