They lack empathy.
Don’t waste your time expressing your opinion. A narcissist will simply shoot you down, as they’re incapable of understanding that feelings exist (outside their own) or why you may be hurt. He/she may be bold enough to call you “sensitive,” or “weak” and advise you to “learn how to take a joke.”
On the flip side, his/her ego needs to be stroked at all times. Neglecting to do so is like stealing candy from a baby – expect one hell of a tantrum!
They thrive on control.
They’re a control freak. Don’t bother making plans for dinner, dates, holidays, or life in general. A narcissist is likely to talk you out of anything and everything that doesn’t meet their needs and/or wants.
Rules are to be challenged; boundaries broken.
They are above the law in every way and have a real issue with authority. Whether at work, in-home, or school, their innate sense of superiority means they regard boundaries as a challenge and find joy in manipulating the restrictions placed on them. In other words, “no” is not part of their vocabulary. So expect a fight around each and every corner.