Infidelity is often touted as a physical act. It has always meant sneaking away to meet someone in person, concealing letters or forging elaborate excuses to cover up your absence. Today, however, relationships face a new frontier of betrayal altogether. Now, it unfolds not just in secret hotel rooms but in the open feeds of Instagram, TikTok, Facebook and other social media platforms.

A single “like” on an old flame’s photo may seem trivial. But this very “trivial” act ignites arguments that feel every bit as charged as catching a partner in a bar with someone else. The main culprit however, is the lack of clear labels for social media behaviors.

Is a late-night comment playful or flirtatious? Is a DM to a colleague professional or intimate? These ambiguities leave couples debating not just actions, but meanings.

One of the major reasons why couples are distressed these days is not necessarily explicit “cheating,” but the lack of consensus or agreement on what counts as cheating. The terrain of digital life has blurred older boundaries, leaving partners in the murky waters of the digital infidelity spectrum.

Here are three primary reasons why digital infidelity lies on a spectrum and is not a binary, for many.

1. Beyond the semantics, it reflects psychological reality. Human relationships bank on nuance and meaning-making. Just as emotional intimacy can exist without physical touch, for some, betrayal can occur without physical contact.

2. Thinking in terms of a spectrum helps couples avoid a false dichotomy; the idea that behavior is either innocent or infidelity, with nothing in between. Recognizing gradations allows for earlier intervention. A partner who admits, “I realize my online interactions with this person are becoming a bit too frequent” has a chance to recalibrate before secrecy escalates.

3. The spectrum model also empowers couples to co-author their boundaries rather than inheriting outdated definitions of fidelity. It shifts the focus from “What do other people consider cheating?” to “What do we, as a couple, agree to protect in our relationship?”

But naturally, even though digital infidelity is not always a direct act of cheating, it still stings. Here are two “harmful zones” of behavior that help explain why online interactions can wound just as deeply as physical affairs.

The Grey Zone: From Harmless Scrolls To Hidden Signals

Most social media activity is innocuous. Liking, sharing and commenting are often what communication scholars call “low-cost signals” which are small, habitual gestures that maintain social ties without necessarily implying intimacy. A quick “Congrats!” on a coworker’s promotion or a heart on a friend’s holiday photo typically belongs to this harmless category.

Trouble begins, however, when these actions start to cluster around a particular person. If one individual consistently receives the bulk of a partner’s likes or comments, especially someone outside the couple’s shared social circle, those small digital gestures take on disproportionate weight. Psychologically, humans are wired for pattern recognition, and repeated signals trigger us to look for underlying intention.

Additionally, research on jealousy induction in relationships found that people sometimes use subtle strategies as a way of managing dynamics in their relationships. Examples include feigning interest in others (“flirtation façade”) or highlighting alternative partners (“relational alternatives”). The motivations behind these behaviors range from seeking reassurance (relational rewards) to retaliating against a partner (relational revenge).

On social media, this can look like a string of likes, playful emojis or inside jokes that, whether consciously or not, function as jealousy-induction tactics. This is why seemingly minor online acts can feel so destabilizing. It’s not just the digital action itself, but the suspicion that it might carry wrongful intent. And once jealousy is triggered, partner responses can vary widely. Some may lash out, others may withdraw, while others may try to “compensate” by investing more in the relationship.

In short, the “grey middle zone” of online interaction where behaviors are ambiguous but emotionally charged, is fertile ground for relational tension. One partner may dismiss it as “just social media,” while the other interprets it as a deliberate signal of drifting attention. It is in this space, between harmless scrolls and hidden signals, that trust is most vulnerable.

The Red Zone: When Secrecy Takes Over

Digital ambiguity morphs into digital infidelity not necessarily because of the act itself, but the secrecy surrounding it. When partners start using alternate accounts, hide message threads or delete comment histories, it represents a clear shift in motivation. The intent no longer comes off as a casual connection because of all the concealment.

A prospective study of newlywed couples found that when one partner perceived the other as hiding something, it reduced marital adjustment and trust. Naturally, it increased conflict over time. The effect was driven by feelings of exclusion that secrecy signals to a partner. Exclusion, to the partner on the receiving end, reads as “You are no longer on the inside of my life.”

Yet another line of research extends this insight, showing that secrecy doesn’t just damage trust once. Rather, it sets in motion a reciprocal cycle. When individuals sense their partner is concealing, their trust plummets significantly. That lower trust in turn makes them more likely to hide things themselves. This causes their partner’s trust to fall further.

In a daily record of two weeks, researchers found that this back-and-forth was visible day by day. One partner’s concealment sparked the other’s, creating a slow but steady erosion of intimacy.

There is a common narrative among many therapy clients who often say, “It’s not the messages that hurt, it’s that they felt the need to hide them.” This is an impactful outcome of a “simple act of flirtation,” that eats away at relational certainty.

What makes it worse in digital contexts is that secrecy can be heavily and symbolically loaded. Phones turned face-down, passwords suddenly changed, accounts logged out after years of open access. Each small maneuver chips away at the sense of safety and shared transparency.

The primary reason digital secrecy feels devastating is because the human brain doesn’t distinguish much between digital and physical betrayal or rejection (as confirmed by a brain imaging study); it registers the secrecy, the exclusion and the rupture in trust as a genuine emotional injury.

Building Digital Trust Together

Given that social media is deeply embedded in daily life, eliminating online interactions is neither feasible nor desirable. The goal is not to avoid digital spaces but to navigate them in ways that preserve trust. This requires couples to shift from an implicit to an explicit negotiation of boundaries. Here are a few strategies that you can start experimenting with.

1. Define your digital boundaries. What counts as “too far” varies dramatically between couples. For some, liking an ex’s vacation photo is harmless nostalgia, but for others, it’s a breach. The key is to articulate these thresholds openly. Clarifying expectations early can pre-emptively lower rates of conflict and bring greater satisfaction.

2. Focus on patterns, not isolated acts. One stray heart emoji is unlikely to destabilize a relationship. But repeated, disproportionate engagement with a specific person may signal emerging attachment. So, notice if the attention is intensifying, diversifying or being deliberately hidden?

3. Use curiosity before accusation. When something online feels uncomfortable, leading with accusation (“You’re obviously cheating”) usually provokes defensiveness. A more constructive approach is curiosity: “I noticed you’ve been messaging X a lot. What does that mean to you?” This is a form of nonviolent communication, which shows that framing observations without judgment creates space for openness rather than conflict.

4. Build digital rituals of connection. You can also transform social media from a source of division into a shared space. This might mean co-creating online photo albums in the form of joint accounts or simply sharing memes throughout the day. Such rituals reinforce the sense that digital life is not an individual escape but part of the couple’s collective identity.

The challenge of modern love, then, is not to retreat from digital spaces but to bring the same intentionality to online interactions as we do to offline ones.

Do you think your digital interactions could interfere with your relationship? Take the research-backed Propensity Towards Infidelity Scale to find out.

A similar version of this article can also be found on Forbes.com, here.