Double narc????

Sorry, if this is not the right place to post this but I am hoping to get some answers here.

Has anyone ever heard of narcs being in relationship with other narcs? Or claiming their partner is a narc when they are actually the ones being narcissists???

This is the situation I am trying to figure out:
I have had a friend for many years, who definitely has some narcissistic traits. Because of her being so self-centered I let our friendship cool off.
Now she and her partner of 17+ years being together split because he fell in love with another woman and cheated on her. I only know my friend's side of the story. I know her ex a bit, he's definitively a "pretty boy"-type, who enjoys getting attention from others.
Now my friend a) claims her ex is a narcissist (which could well be) and b) claims his new girlfriend is a narcissist as well. Apparently he as said things like how his new girlfriend mirrors him so well etc.

After my friend (who is also a colleague, which is why I still occasionally deal with her) did something pretty selfish today I am starting to think that maybe she's the one who's a narc????

Does this make any sense?

Can a narc even be with another narc? Or is she just making things up because she's the narc?