What Really Defines Cheating? Experts Settle Debate Once and for All

A recent Reddit thread has reignited the age-old debate about what truly constitutes cheating in a relationship.
The thread, beginning with the question, “What’s not really cheating but can count as cheating?” revealed how varied and nuanced people’s definitions can be, especially in the age of social media.
Newsweek spoke to Leah Carey, a sex and relationship coach, and Dr. Tammy Nelson, a sex and relationship therapist, to settle the debate.
On the Reddit thread, over 2,000 people chimed in about their experiences and perspectives on infidelity, ranging from the predictable to the unimaginable.
One user, u/Thrillhouse801, shared a personal experience in which his wife was angry with him for weeks after dreaming he had hooked up with her friend. “Not sure if that counts or not,” he said.
Another Redditor, u/Reasonable-Mischief, introduced the concept of “monkey branching,” which they described as “approaching a romantically compatible partner to pursue a friendship with them that’s entirely innocent and platonic…but the intended goal is to keep them in the loop and stay in touch so that you have an exit strategy should your current relationship go south.”
Moving to texting and social media, u/Fairytaalecassy mentioned “intentionally deleting texts so your partner doesn’t see them…If it needs to be hidden, it’s already shady.”
User u/Galactic_Goose_3 pointed to online flirting as another gray area of infidelity, often dismissed as harmless fun.
“Flirting with someone online and calling it harmless fun,” they wrote, implies a level of engagement that might be harmless to one person but hurtful to another, especially if it crosses decided boundaries.
Leah Carey told Newsweek that, despite what we may want to believe, the concept of cheating is far from universal.
“As a sex and relationship coach, I’ve shifted my language away from ‘cheating’ and now use ‘breaks in trust’ instead,” Carey said.
She argued that cheating is a “squishy” term with no single definition, and what one person considers a betrayal might be perfectly acceptable to another.
Carey said that the real issue lies not in the act itself but in the lack of communication about acceptable behavior in a relationship and the ensuing dishonesty in light of it.
“We go through our relationships assuming that everyone else has the same definition we do, and then suddenly find ourselves in trouble because we violated a rule that we didn’t know existed,” she said.
Her advice? Couples should have open discussions early on about their boundaries and what constitutes a breach of trust.
On the other hand, Dr. Tammy Nelson, a sex and relationship therapist, offered a more structured approach to defining cheating.
“Cheating can be defined by three things,” she said.
First, it involves a relationship outside of the primary partnership that threatens or crosses the couple’s agreed-upon boundaries—this could range from emotional affairs to “micro-cheating” behaviors, like maintaining a close relationship with a co-worker that crosses the line of what is acceptable in the relationship.
The second aspect, she said, is the sexual component, which might include anything from sexting to physical encounters.
“Whether it’s mutual masturbation over the internet or a full-blown sexual affair, these acts can feel like a parallel relationship,” Nelson said.
Lastly, she emphasized the importance of honesty: “It’s the secret-keeping that differentiates cheating from micro-cheating,” she said.
Even with no physical or emotional affair, the act of hiding something from your partner, whether a conversation, flirtation or fantasy, can be seen as a form of cheating, depending on the couple’s boundaries.
Carey and Nelson seem to agree on the importance of communication in maintaining trust in a relationship. Whether discussing what you’re comfortable with or revisiting agreements as your relationship evolves, being open and honest is the key.
Nelson suggested couples periodically revisit their “monogamy agreement” to keep it flexible and in line with their evolving relationship to prevent infidelity.
“Talk about things like dreams and fantasies and what type of behaviors constitute crossing the line,” she said, adding that a therapist can be invaluable in navigating these complex conversations.
As relationships continue to evolve in the digital age, the definition of cheating becomes increasingly murky. Today’s couples must also navigate digital and emotional boundaries.
Experts’ key takeaway? Cheating is less about the specific act and more about the violation of trust—something that can only be understood and respected through communication.