I'll find the time to provide the link but there is a a guy who is a clinically diagnosed narcissist and he goes on Youtube to answer people's questions about having a relationship with a narcissist. According to him, a narcissist can get married but it is always for their convenience. There isn't real love because narcissists cannot love another person. The person serves as a useful function for the narcissist. For example, she has his children, performs house duties, provides a second income, etc. Whatever function she serves, she now becomes his primary supply. So sometimes, a narcissist will marry their primary supply, but the supply is miserable of course. When asked why the supply doesn't just leave, he says because the narcissist knows how to play the game to destroy the spirit of the supply. Many times the supply feels trapped and isolated.
Sounds like many stories on Hmong Youtube story channels.