From what I've seen on YouTube about narcissism- it's probably about narcissistic supply- so- getting an intense emotional response from someone. As @Unhumanly. said, it may not be a genuine wish that the person leave. More a threat to make them experience and express an intense emotion. Guilt that they are so hard to live with that their own parents want to be rid of them, rejection and the desire to win back their parents love, fear that their parents could actually cut them off.