You've cracked the code.

You've studied the personality style. You've spotted the red flags. You see the behavior patterns clear as day. And now you're sure you're dealing with a narcissist.

That only leaves one thing left to do: Tell this person that they're a narcissist. Right?

Wrong.

Experts agree one of the worst things you can do in a narcissistic relationship is tell someone that they are a narcissist − even if you are correct. That's because doing so almost always causes more harm than good.

"By definition, narcissistic personality styles are about lack of self-awareness, lack self-reflective capacity," says Ramani Durvasula, a psychologist and author of "Should I Stay or Should I Go?: Surviving a Relationship with a Narcissist." "If you think you're going to say something like this to someone, and it's going to result in a productive conversation, it absolutely will not."

What happens if you call out a narcissist?

Though it's tempting to call out a narcissist, experts say it's important to understand how a narcissist will react to the accusation.

Narcissists can't handle even the slightest criticism or feedback, because it wounds their grandiose sense of self. As a result, no matter how kindly or gently you word it, they will lash out severely if you tell them they are a narcissist.

"You'll get yelled at, guilt-tripped, told that you are judgmental or mean, and probably be given a list of reasons that they think you are a narcissist," says Chelsey Cole, a psychotherapist and author of "If Only I'd Known: How to Outsmart Narcissists, Set Guilt-Free Boundaries, and Create Unshakeable Self-Worth."

Plus, narcissism is a personality style that's extremely resistant to change, so calling them out likely won't do anything to improve their behavior.

"A lot of people think if they could help the narcissist see who they are and see how harmful their behaviors are, then the narcissist would change, or at least wouldn't be able to deny that what they're doing is harmful," Cole says. "But narcissists already know what they're doing is harmful. They just don't care."

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Stephanie Sarkis, a psychotherapist and author of "Healing from Toxic Relationships: 10 Essential Steps to Recover from Gaslighting, Narcissism, and Emotional Abuse," says a narcissist's actions after getting called out follow this pattern: They will deny, accuse and then reverse the victim and the offender in the situation.

"They will punish you by turning things around on you," Sarkis says. "They may also punish you with rage. They may also punish you with silence, like stonewalling, which is acting like you don't even exist."

Durvasula warns people to expect "a big, gaslighted word salad" after calling out a narcissist.

"If you think you're going to say something like this to someone and it's going to result in a productive conversation, it absolutely will not," she says.

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What should you do instead?

Durvasula says the power in recognizing narcissism is not in calling out narcissists, but in seeing clearly what's going on for yourself.

That way, you can make informed decisions about how to proceed with them.

"Now you know how to deal with them," she says. "You know how to have more realistic expectations of their behavior, of how to interact with them, to know what they are and are not capable of."

Durvasula urges extra caution in calling out narcissists in professional settings, such as in the workplace, or in court. Doing so, she says, "can sometimes leave you being perceived as the more difficult or problematic person."

If you must confront a narcissist, Durvasula recommends focusing on specific behaviors in order to avoid labeling someone. For instance, you can try asking them to not look at their phone while you're talking or to stop taking constant selfies.

Just don't expect your words to actually make a difference.

"You're much more likely to have a productive conversation if you point out a behavior than if you ever said someone was a narcissistic person, and even the odds of having a productive conversation by pointing out their behavior is pretty low," Durvasula says.

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Some people may know how a narcissist will react to criticism but still want to call them out anyway, especially if they already plan on ending the relationship.

Cole says that, if you must call out a narcissist, do so knowing what will follow. You should also only do it for your own healing and not with any expectation of inspiring the narcissist to change.

"You need to do so with eyes wide open, knowing you're going into the lion's den, that you're likely going to get berated and criticized and probably told why you're a narcissist," she says. "But only do that if it's necessary for your healing."