The usual reason is that one or both of them are faking happiness. Higher functioning people with NPD are quite capable of bringing their mate to tears before the two leave for a party or dinner with another couple, and then spend the rest of the evening pretending all is well. Both members of the couple usually have their own reasons for keeping up appearances.
- The person with NPD needs to project an image of being perfect and having the perfect relationship.
- The non-narcissistic partner may be trying to avoid being publicly embarrassed, so he or she goes along with the pretense.
- Even worse, the non-narcissistic partner may be afraid to tell anyone the real truth about the relationship.
- https://www.psychologytoday.com/us/blog/understanding-narcissism/202007/can-narcissist-have-happy-marriage
