Simply put, narcissists like to mess with you. They need to feel superior, so if they can delight themselves by toying with your emotions, they will do it. This is why they will sometimes gaslight you, throw a hot potato in your lap (narcissist technique), … anything to see you react, then they point their finger at you redirecting and blaming.
Check out this video about 8 Tactics Narcs Use to Goad You.