Narcissists view all agreeable relationships as painful, arduous, degrading work. They resent having to be nice to anyone so much that they actually feel entitled to compensation from that person for the effort they made.
They aren’t just agreeable when they don’t really feel like it, they’re sickeningly sweet when they don’t need to be. This exaggerated behaviour makes others uncomfortable because instinctively you know it’s manipulative, you just don’t know what they want or why they feel the need to be insincere.
Eventually, when a narcissist isn’t coercing the desired resources out of you, they explode with an entitled tantrum, accusing their target of withholding something that “belongs” to the narcissist: your time, your money, your property, your body, your efforts, your social network, your career… whatever it is that they’re trying to get at, they see you as an obstacle in the way between them and that thing.
As a human obstacle, they don’t see their mercenary tactics towards you as unethical. Their treatment of you is completely justified in their own mind by the belief that they are entitled to have whatever they desire. Posing an obstacle makes you the bad guy in their mind.
If you’re non-compliant about handing it over when they went to all the effort of being “nice” (manipulative) to you, then they become enraged. You’re supposed to follow the “rules of niceness” which is: if I’m doing the bare minimum of human decency, then you owe me whatever price I name.
That’s their interpretation of social decency; it’s not about being decent because they should be, it’s about extracting resources from everyone around them.
You may have had one conversation in passing with this person, but the second you popped up on their radar is the same moment they kidnapped your reputation and held it to ransom. That’s why they make people feel so uncomfortable and anxious… because you will have the instinctive sense of crossing paths with a predator.
If you don’t cough up whatever they believe they’re entitled to by whatever arbitrary deadline they set, then the narcissist will assassinate your character.
If you feel violated, it’s because you literally just got social-jacked. It’s harder to pinpoint than an actual carjacking, but no less real.