Can a Narcissist Be Faithful in a Relationship? (According to Experts)

Narcissists are often thought of as being unfaithful in relationships, but is that really the case?

Some people believe that narcissists only have one partner at a time, while others think they’re just as likely to cheat on their partners as anyone else. Some even believe that they can never be monogamous.

So, we asked experts, “Can a narcissist be faithful in a relationship?” 

Here are their insights:

They are only faithful for as long as they receive preferential treatment and top priority

The number one person in a relationship with a narcissist is themselves. If both people in the relationship can agree with this, consciously or not, they can continue to be faithful to the other person in friendship or romance.

The catch is this: They are only faithful for as long as they receive preferential treatment and top priority.

Although narcissists may be skilled at hiding other aspects of their personality, these unreasonable relationship expectations often give them away.

Narcissists place their needs over their partner’s to fuel their self-worth

Narcissists place their needs, such as praise and attention, over their partner’s emotional well-being. As long as their sense of control and elevated status is kept in place within the relationship, they are not more likely to be unfaithful than any other partner.

The thing for them is they aren’t in a relationship to know another person or to share an experience; they are interested in receiving a “narcissistic supply,” which is the preferential treatment they set themselves up to receive.

This supply is what they need to fuel their sense of self-worth. Without the constant assurance of another person engaging them positively, desiring them, or flattering them, they cannot maintain their self-image.

Related: Are Narcissists Insecure?

They seek out vulnerable partners who reinforce their image

The difference between you and I and the narcissist is this: They must always be “amazing“ and receive reactions to this end. While we can accept that we have strengths and weaknesses and are not always universally praiseworthy or exceptional, they cannot do this.

They seek out open and vulnerable partners with whom they evoke a strong reaction that pleases them and reinforces their image.

They maintain the relationship through manipulation, understand how to hurt their partners, and will use gaslighting or outright lies to maintain their control over the other person.

Related: How to Respond to Gaslighting

In this kind of way, narcissists are truly faithful to themselves.

The narcissist’s loyalty is about what they continue to extract from their partner

Their partners are the audience in this relationship. If they stop applauding when expected — giving the supply — the narcissist knows that it is time to move on to the next person who finds them “amazing.” They are only faithful to who they can exploit.

They will drain their partner of empathy, encouragement, time, resources, or anything else that makes them suitable for the narcissist.

The narcissist’s loyalty isn’t about the other person but rather what they continue to extract from them. Their partners unknowingly try to satisfy a void, like a black hole; nothing will fill it.

Essentially, their faithfulness isn’t a great quality to the prize. If the partner of the narcissist holds on long enough, they will not be rewarded, but instead find the narcissist using their exit strategy, devaluing the relationship and eventually discarding them.

Yes: As long as they see it is in their best interests

Narcissists, by definition, focus on what’s good for them in their own estimation. They put themselves first and foremost always. Any effort to “help” another person is calculated in terms of what the benefit will be to the narcissist.

The short answer is yes. Narcissists can be faithful to a relationship in the sense that they don’t sleep with anyone else. As long as they see it is in their best interests, that is.

The long answer is, if you’re in a relationship with a narcissist, someone who always focuses on themselves first and you as a vehicle to their own fulfillment or gratification, what kind of relationship are you in? How does faithfulness apply in this kind of relationship?

Faithfulness is often mistaken for no sex with another other than your partner. Though monogamy is certainly a part of the mindset around being faithful to a partner, it is not the only answer.

Being faithful in a partnership means that both partners are looking for what is best for the relationship as well as themselves. Being unfaithful in this context might show up as being emotionally intimate with someone else in a way your partner feels is inappropriate. It might show up as spending money secretly.

“Unfaithful” has broader implications in a partnership than just sex. Sex is the end of the line on the road to “unfaithful.” There are a lot of stops on the way, including the above, as well as many more tell-tale signs.

A strong marital partnership is based on at least a win-win perspective, if not a triple win.

Win-win means that each person wants the other to be successful as well as themselves. A triple win would imply that they see their family as having a positive impact on the community and culture around them; their success is linked to one another and their sense of a greater good.

Narcissists, by definition, come from an “I win, you only win if I win” perspective. That means a good deal of the time they’re willing to sacrifice their partner’s interests for their own.

They’re often not conscious of this.

If you accuse a narcissist of being all about themselves, no doubt, they will give you a hundred and one reasons why the problem is really you, not them. That you are self-centered and they are marital superstars.

They are masters of denial and gaslighting; they have to be to believe that they are amazing and everyone else is in a supporting role.

What you can count on with a narcissist or even people who just tend to be narcissistic is that they will always believe they are right and good and will not admit fault unless they see an advantage for themselves.

This is the opposite of a true partner, who makes themselves vulnerable, admits their shortcomings, and asks for support in reshaping their behavior from their partner and others.

What that means is faith has already been broken. Remember that they never keep the marital vows fully and completely unless it’s in their best interest. You will never be equal or come first with them.

If we look at faithfulness as more than sex, the narcissist has broken faith from the very beginning. The narcissist promises to enter into a win-win partnership. That’s what marriage vows are all about. They agree in bad faith.

The only person they remain faithful to, in every sense of the word, is themselves

It’s not impossible for a narcissist to be faithful in a relationship. However, the odds are that if anyone is going to cheat, someone with a narcissistic personality disorder will be more likely than someone else to cheat.

Shame, unworthiness, emptiness, and fear are usually at the core of the narcissistic person.

These feelings are buried so deep, and the narcissist is so disconnected from any real sense of self — to admit anything other than superiority is to lose everything. They will stand behind their carefully crafted mask of perfection at all costs.

Those who have experienced a relationship with a narcissist know: It’s a whirlwind.

The narcissist is shrewd, an expert at manipulating people. They see no problem exploiting their partner’s strengths or weaknesses as a ploy to get their needs met.

The narcissist knows how to turn on the charm, love bomb, and then withhold — become cold, dismissive, or angry.

Related: What to Do When a Narcissist Is Mad at You?

Studies show that the intermittent reward and excitement of “Is my narcissistic partner going to be nice today?” (and many who are in a relationship with a narcissist may not realize it right away) activates the same place in the brain that’s pinging when someone gambles.

It shows that this cunning tactic the narcissist uses creates somewhat of an addictive component. This strategy is known as Intermittent Reinforcement, and it adds an additional dysfunctional layer, commonly called a “trauma bond,” to the relationship.

The dopamine rush that the partner of a narcissist experiences when things go well can be hard to let go of. People caught up in this may misinterpret the dopamine and label it love.

Think of that because they’ve never experienced something this intense with anyone else before, that this is the real deal, and double down on trying to make it work.

Related: How Does Narcissism Affect Relationships?

The narcissist is quick to point out that their anger or unhappiness is because their partner is doing something wrong. Their partner, in turn, will attempt to modify their behavior and do what they can to ‘mollify’ and ‘coddle’ the narcissist since maintaining the peace is much easier than being slammed by another angry outburst.

This dynamic makes it so hard for those caught up in an abusive or toxic relationship to leave.

These people slip through the radar because on outwardly, they don’t appear narcissistic. However, they possess all the other characteristics, even though their clandestine nature makes it harder to detect or label them a narcissist.

Narcissists constantly seek validation and admiration from outside of themselves

Because the narcissist is empty (completely detached from what’s at their core), they need external forces, namely admiration and validation, to feel good about themselves.

Now, to some degree, many non-narcissistic people do this too. However, they are still connected to themselves or actively working on connecting and understanding themselves and, to some degree, realize that true happiness and fulfillment come from within.

Thus, they aren’t solely reliant on others’ admiration to fuel their self-esteem.

Because narcissists are incapable of this, they constantly seek validation and admiration from outside of themselves. Unfortunately for them (and everyone involved), no matter how much they get, they will always need more. There will never be enough, ever.

This insatiable quest for attention and admiration is called “narcissistic supply.“

They have no problem venturing outside the relationship to top up their narcissistic supply

If you are in a relationship with a narcissist and life is busy — you’re probably exhausted and may be unable to keep up with their demands, give them the attention and admiration that they crave — a narcissist may decide to see what exists outside the relationship.

Or, in some cases, even if you’re working overtime to keep them happy, most narcissists are easily ‘bored’. Many have no problem venturing outside the relationship to top up their narcissistic supply.

And what better, more thrilling way than by engaging in an affair?

Narcissists can be very charismatic, so the idea of conquest can be very
appealing. The thought of an affair hurting their partner doesn’t have quite the deterrent that others may have because they cannot often feel empathy.

A narcissist will feed off the energy they get from this new person — sometimes the thrill of getting away with it as well. Because it’s all about them, they are less likely than someone else to take a look at themselves. Question this desire. Seek to understand what’s really going on instead of cheating.

Narcissists when it comes to cheating

Because honesty is never the narcissist’s policy — at least when it comes to them getting what they want — short of catching them cheating or coming up with hard, irrefutable evidence, you may never know if the narcissist is actually cheating.

If accused of cheating, they gaslight

Narcissists weave a very intricate web.

If caught cheating, they’ll assume the least amount of responsibility

If caught cheating, a narcissist will do whatever they can to assume the least amount of responsibility.

Being with a narcissist is a toxic relationship

Most relationships with a narcissist are toxic relationships. They are not reciprocal; one person gives, and the other takes. One person is in control, and the other acquiesces.

Related: Why Do People Stay In Toxic Relationships?

You may have heard that in order to love someone else, you have to love yourself. Contrary to popular belief, a narcissist does not love themselves. The world they’ve created isn’t real.

It isn’t grounded in the substance and depth of a true, reciprocal relationship, in which couples support one another equally, share their insecurities, and would never think to use the insecurity of the person they love as ammunition in a fight or as a way to get what they want.

From challenges to failures, all the things we face in life are the things that shape us and make us stronger.

In a broader sense, it can be said that all narcissists cheat. Cheating on a test, lying in a resume, and telling someone what they think they want to hear in order to get what they want are all forms of cheating.

If you are in a relationship with a narcissist, the probability of them cheating on you is likely. But even if they don’t cheat on you in the traditional sense, you are still being cheated; the only person they remain faithful to, in every sense of the word, is themselves.

They may not express it the way their partner does, but there is still a level of love for them

When someone describes their partner as being a narcissist, what it means in the therapy world is that the person possesses a personality disorder. A person who has a personality disorder does not have a truly diagnosable biological issue from a neurological point of view.

In short, medication isn’t going to change their behavior because they likely sprang into the world with the perspective they hold today.

The way a narcissistic personality disordered person views themselves and their world is often one where they hold themselves in high regard, as superior to those they are in a relationship with.

However, it doesn’t mean they don’t have a moral compass or a set of ethics and values. Just as anyone who wants to have self-respect and live by their own code of personal standards, so do NPD partners.

While it may be easier for an NPD to view themselves as someone being worthy of greatness and lacking humility, these individuals are still capable of having love for their partner. They are aware they can inflict pain on the person they are in a relationship with.

The NPD partner’s love may not look the same way or be expressed the way their partner does, but there is still a level of love that exists for these individuals.

There is a stereotype that someone who is considered a narcissist is someone who puts their own needs above others. While that is often true, it doesn’t mean NPDs don’t have a set of rules or standards they have put in place for themselves around their ways of living life.

Related: 60+ Signs You’re Dealing With a Narcissist

They often still have the ability and desire to follow these personal rules in order to be able to continue to hold themselves in high regard. However, it may be difficult for an NPD partner to empathize with how the infidelity will impact their partner once they have decided to stray.

In those instances, NPD partners can cut emotional ties quickly and succinctly.

Most, but not all, narcissists are cheaters

Most narcissists are cheaters. But not every narcissist is a cheater. The reasons why vary. One big reason is that not every narcissist can pull it off.

Just like there are different levels of narcissists who cause trouble with the law, there are different levels of narcissists who cheat.

It also depends on what you consider cheating. Some are just talk and no action. Some try to talk without much luck. Others just watch adult videos instead of paying attention to you. Many do it secretly, but others do it blatantly. Yet the biggest cheaters go around sleeping with whoever they can.

Shameless or wannabe public cheaters

This type follows a bunch of opposite-gender people on Instagram. They “heart” all their skimpy photos and publicly comment on how hot they are. If this is the case, this type of partner is a shameless cheater. They want you to see it and get jealous.

If you confront them, they will deny it and call you insecure or controlling. They’ll make you feel ridiculous for calling them out. But they know exactly what they’re doing. Their actions are to make you jealous specifically.

In case you’re wondering if they actually get with any of these people— it depends. They may or may not get with them in real life. But they will certainly try.

Secret or anonymous attention seekers

Some narcissists will try to meet up with random people on Craigslist or dating apps. This way, they can stay more anonymous.

They can swipe through photos of people from the comfort of their own couch. They won’t risk any face-to-face rejection. And they don’t have to put forth the effort to try to meet someone. It’s an easy way to go outside their social circle to find someone to cheat with.

What do they do once someone agrees to meet up with them? They may just take them to dinner and act like it’s a date. Some just leave it there. These narcissists may not consider a dinner date cheating as long as they don’t have sex. In their mind, they did nothing wrong.

If you are not home, some may take the new person back to the home you share together. If you truly feel like someone else had sex in your bed while you were away, they probably did!

Neglectful cheaters

This type will watch and enjoy adult videos all the time rather than have sex with you. It makes you feel bad like you aren’t as attractive as the characters they’re watching. This is done on purpose. They know how it makes you feel and like the result. Those who feel bad want others to feel bad.

If they have the money, they’d rather talk to a phone sex operator than give you affection.

Speaking to or seeing a different person always makes them feel desired by many people. You are just one person. So you can’t fulfill their insatiable need for many admirers.

Plus, if you are neglected, it just makes you try harder. In their mind, you want them more. But you are just boring to them. They make you feel this way, too.

Related: Warning Signs Your Partner Could Be Cheating

Super-skilled cheaters

This is the type with multiple partners on speed dial. And they’re always on the lookout for new ones.

They actually do meet up with a lot of these “lovers.” And they’ve got each of them under their spell. They can come and go as they wish.

If they want a break from their primary partner, they have somewhere to go.

Two-partner narcissists

Some like having a main partner and another side person. The main partner is likely their spouse or the one they live with. They have been together long-term.

Once the narcissist has one partner trapped at home, they test the waters to see what that partner will put up with. If they can start disappearing without being questioned, the narcissist will begin cheating more blatantly.

Sometimes it’s harder to detect. If the narcissist says they are traveling for work and going for a day or week, how do you know if it’s true? They may be spending time meeting up with their side partner instead.

If the main partner threatens to leave or actually does, the narcissist will say anything to get them to stay. They will probably promise to change. The main partner wants to believe them, so they come back. Unfortunately, this doesn’t end well. The cheating often becomes even worse after this.

Sometimes the main partner does not want to acknowledge the cheating. They either know or don’t want to see it. So the affair goes on for years without the partner knowing.

The irony is that it’s better to be the side partner. Why? Because the narcissist treats the person better who doesn’t live with them. Once the narcissist has you trapped, they feel like they don’t have to impress you anymore.

They keep a circle of opposite-gender “friends” around for attention

Some narcissists will keep a circle of opposite-gender friends around them. Their attraction level does not matter — as long as they give them attention.

Who are these “friends?” Some like the attention themselves. The narcissist leads this person on, and they both enjoy the attention.

Why does the “friend” put up with it? Because they may be unattractive and don’t have any other prospects. They’re just glad someone is talking to them. Others are typically really nice people who feel sorry for the narcissist. They keep in touch with the narcissist out of pity. But the narcissist doesn’t understand this.

In the narcissist’s mind, this person has a crush on them. If the “friend” knows about the narcissist’s partner, they will use this person to complain about their partner. It is just another way for them to get attention.

It’s not uncommon for these “friends” to get weirded out by the narcissist. Over time, they respond less or stop responding altogether.

This is arguably the least harmful type of cheating. There sometimes aren’t even romantic words exchanged. But it’s still secretive, attention-seeking, and done behind their main partner’s back.

Non-intimate narcissists

Some narcissists simply don’t like sex that much. The bad news about this is that they will probably go years without having sex with you. Some can’t get other partners. There are also narcissists who believe it’s wrong to cheat, so they don’t do it.

Do they still lead others on and try to get attention in other ways? Maybe. But not all do.

How to decipher whether your partner is cheating or not

Whether your partner is a narcissist or not, no one deserves to be cheated on. You’ll need to decide what’s acceptable to you and what isn’t. If you need relationship help, hiring a relationship coach can be useful.

A relationship coach can help pinpoint your pitfalls. They’ll help you correct them and have better relationships. It can be super helpful to hire an expert who is always in your corner and pushes you to succeed.

No: They tend to be dishonest and manipulative in general

Relationships with narcissists are never easy, and understanding the kinds of behaviors that lead to issues can help us avoid them. When it comes to commitment, however, it can be especially tricky.

Many think that a narcissistic person will only have one relationship in their life: marriage. However, this doesn’t seem to be accurate.

Many people with this disorder also have a more impaired sense of self-worth than others; they also tend to be dishonest and manipulative in general. These behaviors make them seem like they could be unfaithful as they’ll believe their own lies so often that it becomes easier for them to trick others.

People with this personality disorder usually feel no guilt over hurting others, believing they are superior without any faults or imperfections.

Related: Do Narcissists Feel Guilt, Remorse or Shame?

The word ‘narcissist’ makes many people uncomfortable, but it’s actually a term used by psychologists who study the personalities of others. Narcissistic disorder is an illness caused by a combination of thinking patterns and behaviors considered to be exceptionally selfish and self-centered.

In short, narcissists believe they are far above average intelligence, so they expect everyone around them to fall in love with them instantly.

Narcissistic people usually ignore red flags because they believe special treatment will help them get what they want. More often than not, though, these behaviors backfire on their own lives as those around them feel trapped and unable to escape from their web of lies and control.

A narcissist is incapable of committing; they’ll likely turn their attention elsewhere

Narcissistic people are often considered desirable and charming, but both feelings are false. Dating someone with this trait can be frustrating, but not knowing what to do only causes more unnecessary agony for both parties involved.

A narcissist is incapable of committing, especially to love and all the other aspects of life you’d like a relationship to have; instead, they’ll likely turn their attention elsewhere.

In fact, someone can have a loving heart and be very kind or cruel and mean but still have this personality disorder.

Although some narcissists may be faithful, their risk of cheating is high

Individuals who display the pervasive pattern of grandiosity, need for admiration, and lack of empathy (required to qualify for the diagnosis of Narcissistic Personality Disorder) make decisions based entirely on the likelihood of gratifying their desires and wishes.

They would, therefore, turn down an opportunity for sexual gratification only if they found the encounter likely to produce some unacceptable secondary result (e.g., a spouse’s anger, separation, scandal, extortion, STD, etc.).

The narcissist’s lack of empathy and inability to reasonably appreciate their own faults and weaknesses hinders them from developing healthy relationships.

Unless it might somehow be to their advantage, narcissists are unconcerned about the feelings and wishes of others. They are ruled instead by left brain motivations and have little awareness of many of the motivational influences of their right brain hemisphere.

Although there is considerable connection and redundancy, the two sides of the brain — the left and right “hemispheres”— relate to the world in fundamentally different ways.

The right brain collects information about the external world from our sensual perceptions. It passes that information to the left brain, which constructs a model of reality, a “virtual” world that we use as a guide to fulfill material and organizational goals.

The left brain employs our language and physical capacities to secure food, wealth, power, and useful property — often by manipulating others. The left hemisphere is acquisitive and competitive and divides people into categories to simplify and control them.

Unlike the left brain, the right cares about people and things other than just the self. It sees the ways in which people are similar and united and is responsible for humility, compassion, and a sense of community.

Motivation from the left brain ensures that people seek food and shelter —and is even responsible for the scientific research that enables understanding of how the brain functions.

Right brain motivation, on the other hand, leads people to seek the gratification that comes from enjoying friends and sharing affection with loved ones, motivations that elude the narcissist.

No, and if they are, it is fleeting or for a deeper self-serving reason

Narcissists, at their core, struggle with low self-esteem and a poor sense of self. They operate on their terms, seeking self-gratification and constant validation to fill the void of how empty they feel. Having their ego stroked is a top priority, and the cravings for attention are insatiable.

Somatic narcissists, those obsessed with looks and their bodies, are most likely to cheat. They flaunt their bodies, flex their muscles, and brag about the number of times other people hit on them.

Somatic narcissists use their sexuality to gain control in relationships and prove their desirability and status, but really, deep down, it feels like an antidote to their low self-esteem.

Infidelity is any action or state of being unfaithful emotionally or physically to a spouse or other sexual/romantic partner.

What constitutes infidelity should be defined by each partner in each partnership with no assumptions or expectations that “the other person should just know what is or isn’t infidelity” present.

This could be emotional or physical. What you think is innocent flirting could be defined as cheating by a partner.

Related: How to Get over Infidelity Pain

As you can see, a narcissist craves validation and attention like oxygen. Without it, their false self dies, and their true self is vulnerable with low self-esteem at the core, feeling starved off, and can’t function.

The term narcissist is overused in society. It depends on if there is an actual diagnosis and, if so, how the NPD presents.

For a person to be diagnosed as a narcissist — meaning they have Narcissistic Personality Disorder — nine criteria need to be met, and there needs to be clinically significant impairment on their ability to function.

Due to the nature of this disorder specifically, typically, it is those around (significant other, family, friends) the identified patient who suffer more than the patient.

For example, entitlement, aggression, and the tendency to take advantage of others. This would be associated with symptoms of narcissistic personality disorder.

They will tell their partner they’re faithful because they demand faithfulness from them

Narcissists will tell their partner they are faithful because they demand faithfulness from their partner. A narcissist needs to be the center of their partner’s world, and they will demand absolute loyalty from their partner.

Narcissists are often charming and will tell their partners that they would never lie or cheat, but their words cannot be trusted.

One of the key characteristics of a narcissist is a lack of empathy, so they can cheat without feeling guilty about hurting their partner. They have no real love for anyone but themselves, so they can create a path of destruction with no remorse.

Narcissists are also experts at gaslighting.

If you’re involved with a narcissist, it can be frustrating and emotionally draining as you try to navigate the relationship.

It takes two dedicated people to make a relationship work, and the narcissist will never put in the same level of dedication as you will, leaving you anxious and confused.

What matters to one narcissist may not matter to another

The idea that people with a narcissistic personality disorder or strong traits of narcissism are incapable of sexual fidelity may make intuitive sense, but it’s simply not true. This is because what matters to one narcissist may not matter to another.

If one narcissist values sexual conquests, they may indeed be incapable of placing fidelity towards their relationship above that desire. But a different narcissist may value money, prestige, or even a position in a religious organization more than sex. In that case, the higher goal would be more motivating.

Also, we need to account for libido because not everyone has an equally strong sex drive. You can also add sexual performance issues because if a narcissist has problems performing sexually, they certainly won’t put themselves in a position to fail by pursuing other partners.

Narcissists may have some traits in common, like excessive self-focus and allegiance to themselves over others, but to assume that this means they will stray in a relationship is an oversimplification.

Yes, if being seen as sexually appealing and robust is important to them

The best way to know what a narcissist will do is to figure out what matters most to them. They will prioritize that goal over others reliably. So yes, if being seen as sexually appealing and robust is important to them, they will likely try to have many sexual partners with little concern to anyone else’s feelings.

Yes, but only for their gain

Narcissists are incapable of being empathic to others’ feelings, nor do they want commitment, so their capacity for falling in love and maintaining a relationship based on true commitment is nonexistent.

However, they can still be faithful solely because it makes them look good to other people or because it feeds their ego to hear praises from other people on how ideal the relationship is or how good of a partner they are.

Narcissists can only be faithful if their partner or supply fulfills their needs

They don’t really engage in the give-and-take process that most normal relationships undergo; they always just want to assert control and dictate their terms.

If their victim agrees, they can be as faithful as they want until it no longer works in their favor.

Yes, only because they run out of supply

Some narcissistic exes come back because they realize they are not as accepted by other partners as you were.

Therefore, they want to return to the sense of entitlement you provided, not because there were any actual feelings of attachment. They can only be faithful because you, as their supply, still work.

Narcissists can be faithful to their partners if they can meet their needs

Narcissists are often seen as being unfaithful and incapable of commitment, but that is not always the case. Narcissists can be faithful to their partners if they are in a relationship with someone who meets their needs.

They are capable of forming deep emotional connections with their partners, and if they meet the right person, they can be faithful to them.

Narcissists often need someone who is able to give them the attention and praise they crave from other people. They want someone who will make them feel special and important. If you can provide this for your partner, they can be faithful to you.

Related: What Does a Narcissist Want in a Relationship?

Narcissists are also known to be promiscuous, which is why it is hard for them to commit. However, some narcissists can be faithful and monogamous.

A narcissist’s ability to stay faithful depends on the person themselves and their relationship with their significant other.

Narcissists are known to be self-centered and manipulative. In a relationship, they tend to put their partner on the back burner. But that doesn’t mean they cannot be faithful.

Many people who have been in long-term relationships with narcissists say that their partners were very committed and loyal to them as well as their family members.

People with NPD may lack emotional guardrails that serve as buffers against reckless behavior

If faithfulness means the absence of physical or emotional cheating in a relationship, then yes, a person with Narcissistic Personality Disorder (NPD) can be faithful.

There is nothing about NPD that inevitably causes a person with that diagnosis to cheat on a partner. In fact, despite popular belief, people with NPD can feel empathy, guilt, remorse, and other moral emotions.

There is, however, an unofficial subcategory of NPD called malignant narcissism, which can be seen as a combination of classic NPD traits with those of Antisocial Personality Disorder (symptoms of which include manipulation, lying, a lack of moral emotion, and a lack of caring for others).

People with malignant narcissism may not, in some cases, feel the moral emotions that lead them to remain faithful in relationships.

In short, people with all forms of NPD may lack some (in some cases all) of the emotional guardrails that tend to serve as natural buffers against hurtful and reckless behavior in relationships, but no outcome — for anyone with any mental health diagnosis — is preordained.

Very few narcissists can maintain emotional and sexual faithfulness

Narcissists demand faithfulness. However, it goes only one way with them. While hypocritically abandoning the relationship, many narcissists demand loyalty from their spouses.

In some instances, this involves cheating on their partners without feeling guilty. Very few narcissists can maintain emotional and sexual faithfulness.