They do not love themselves?
They don't feel love. They are obsessed with themselves. Not the same thing as love. They vacillate between self adoration and self loathing. They feel rage and fear. They are either better than everyone else or feeling like they have it worse than everyone else because they are always losing and wanting something more. Supply, respect, ect...Someone always has more or better than they do and they want it. They live in a state of jealousy, fear, rage, envy, greed, self pity, grandiosity , sarcasm, disgust, fake phony false persona's, con, and manipulation of others. They USE people, they don't love them or themselves. They see what you have that they want and they take it. All the rest of it is for show, pretend. They are easily bored with what they have and are ALWAYS looking over their shoulder to see if the grass is greener somewhere else.
A relationship with a N or P is the farthest thing from love which you are ever going to find.
So many come on here and look for clue's and answers which may show or prove that they do somehow love, if even themselves.
Sorry hon, they don't. They don't love you or anyone else. They are not designed that way. They are wired to use, take, devalue, and discard. They are selfish, self serving, and not the slightest bit interested in how their bad behaviors affect anyone else.