Infidelity extends beyond sexual or emotional affairs and can manifest through seven seemingly ordinary behaviors, according to UK relationship expert Tracey Cox. These actions, often unnoticed by the individuals performing them, can inflict significant damage on a relationship, eroding trust and intimacy.

Cox identifies comparing a partner unfavorably to others as a major red flag. This occurs when one partner consistently uses someone else as a benchmark, highlighting their partner's perceived shortcomings. For instance, a partner might frequently mention a friend's wife, suggesting she is more relaxed or adept at balancing work and children, leaving the other partner feeling inadequate.

Another behavior described is idolizing other women. While admiration can be normal, incessant praise and fascination with other women, particularly when a partner feels neglected, can cause distress. This can create a sense of competition and diminish a partner's self-worth, especially when contrasted with someone perceived to have more beauty, money, or attention.

A critical indicator of potential infidelity is telling someone else first about significant life events. Cox explains that the partner should be the primary confidant for both good and bad news. When a partner instinctively calls a family member or friend before their significant other, it signals a weakened bond and a 'displaced primary attachment,' undermining the relationship's importance.

Continuing to be friendly with individuals who have hurt or upset a partner, especially when done secretly or by dismissing the partner's feelings, constitutes a loyalty test that is being failed. This behavior suggests that the individual's allegiance does not lie with their partner, creating a sense of betrayal.

Sharing rituals, such as watching a favorite television show together, is also highlighted. Watching the finale of a show that a couple has followed for seasons alone can be deeply hurtful, as it disregards the shared experiences that foster connection and a sense of 'us against the world.' These small, shared moments are crucial for maintaining intimacy, especially in long-term relationships.

Dismissing a partner's opinion while readily agreeing with a friend who expresses the same sentiment is another form of disrespect. This can make a partner feel unheard and less intelligent, suggesting that their views hold less credibility than those of outsiders.

Finally, maintaining contact with an ex-partner under the guise of shared interests, particularly when it involves significant effort or causes a partner distress, can be detrimental. While amicable breakups occur, if the contact continues with the same intensity years later, it may indicate that something more than friendship is being maintained, potentially leaving a part of the individual tied to the past relationship.

Cox advises individuals who suspect they might be exhibiting these behaviors to ask themselves if they would be comfortable with their partner witnessing their actions. She emphasizes the importance of prioritizing the partner as the first point of contact for significant news and protecting shared rituals. A simple 'phone test'—considering how one would feel if their partner examined their phone—can reveal underlying issues of trust and hidden activities. Giving one's partner central stage when they speak and being honest about the true nature of contact with past partners are also key to fostering a healthier relationship.