If the narcissist acts in a way that lacks due seriousness or respect, you can do this. Narcissists are used to treating people bad. They have a habit of disrespecting their targets. They treat them like doormats. They walk all over them. Because they know that they can get away with it. The narcissist sees you as a video game. They don't take you seriously. Because they're so used to people not holding them accountable. But there is something you can do if the narcissist starts playing games with you. There is something you can do if they start to get out of line. There is something you can do to put them back in their place. The narcissist may be playing games with you. Maybe they failed to fulfil a commitment. Maybe they're not cooperating with you. Maybe they're disrespecting you. And it may just be a test to see how you react. When they do this, you need to keep them in line. You need to set the standard for what you expect from them. Or else they will get worse and worse. Because they have little or no control over their own behaviour. But this is what happens when people have been with the narcissist for a few months.
The narcissist starts disrespecting them. Because they didn't set the standard of behaviour for the narcissist in the beginning. They let them get away with a lot of things. So now they think they're untouchable. Because maybe in the beginning, you were afraid of losing them. So you feel like you can't confront them on the things that they're doing. You feel like you're not allowed to express your disapproval. When the narcissist plays games with you or does anything out of line, you have to correct them. You have to set the standard. Send them a text message stating that you do not appreciate what they said or did. And tell them that if they repeat the same behaviour again, you will leave them and move on with your life. Because that tells them that you're not afraid to walk away. Which is something that very few narcissists have been told before. They're usually the ones who discard their victims. So when you do that, you're flipping the script. By telling them that you don't appreciate what they said or did. By telling them that if they do it again you will leave.
When you do this, the narcissist is left with two options. They will either cooperate with you. Or they will leave. So either way, you win. Even if they leave, at least then they will be someone else's problem. But if they are willing to correct their behaviour, you should expect an apology. When you do this, you are sending a message to the narcissist that you are not going to accept their dysfunctional behaviour. But when you do this, you have to mean it.
You cannot be afraid to leave the narcissist. Because they will test you. It's like when your pet has fleas. You have to attend to it very quickly, before it spreads and gets out of control. You have to attend to it right away. Or else they will never learn to respect you. So when the narcissist starts playing games. When they start to get out of line... Send them this text message. Tell them you didn't appreciate what they said or did. Tell them that if they repeat that kind of behaviour again, you will leave. I guarantee that they will either correct their behaviour or they will leave you. But either way, you still win.