There are also other reasons, particularly regarding isolating you from other people. The narcissist fears that people who care about you will notice the detrimental impact the relationship has on you.
They also fear that others will validate the reality of the situation which undermines the ardent work the narcissist has been doing in convincing you that it is all in your mind.
Furthermore, they fear others who are concerned will influence you by saying ‘what’s going on is not ok’, and you may just flee.
The fear here is all about being caught out. Either by you saying no more & walking away, or by others calling them on their behaviour.
Exhibit B – The two faces
Similarly, the narcissist will show different faces, one for when in public and the secret one kept just for you.
The secret face is the one stripped of the mask, the real person. This person uses you as supply, feeding off the process of you losing yourself, getting a payoff each time your heart and soul breaks a little further.