I read this today on a website and it was so clear and commonsense that I wanted to share it.
In order for a marriage to succeed, there must be intimacy. In order for there to be intimacy there must be empathy.
Narcissism = no empathy = no intimacy = marriage doomed to fail.
It was true in my case, and although I lasted 30 years in a marriage with a narc, I want to make it clear that I survived, I did not thrive. Some members of this forum have asked if there were good times, or how I managed his behaviours. I can and have answered those questions but the bottom line is this - your marriage with a narc will fail because of their lack of empathy. It is pointless to look for bandaid solutions or to struggle on hoping that things will get better.
If you are willing to settle for a life without intimacy, which becomes increasingly lonely and isolated as you age, then by all means struggle on - otherwise get out when you can. You might still be lonely as you grow old, but at least you won't be in the cruel, lonely world created by living with a narc.