Adultery Is No Crime in Much of the World, but the Law Still Punishes It Unevenly

The broad trend is clear. Over the past few decades, courts and legislatures in many democracies have moved away from treating adultery as a public offense. In 2018, India’s Supreme Court struck down Section 497 of the penal code, a colonial-era provision that criminalized adultery in a way that treated women almost as the property of their husbands. The court called the law unconstitutional and rooted its ruling in privacy, dignity and equality. South Korea’s Constitutional Court reached a similar conclusion in 2015, ending a criminal ban that had sent tens of thousands of people through the justice system over several decades. In the United States, many old adultery laws remain on the books in some states, but prosecutions are now rare and courts have increasingly viewed intimate conduct through privacy protections shaped by modern constitutional law.

Yet the retreat from criminal punishment is far from global. In several countries, adultery remains an offense under penal codes influenced by religion, colonial law or both. In parts of the Middle East and Africa, and in legal systems that apply religious family or morality laws, adultery cases still reach police stations and courtrooms. Human Rights Watch and Amnesty International have repeatedly documented how such laws are enforced selectively and often with severe gender bias. In some jurisdictions, the evidentiary burden is technically high, but in practice cases arise from pregnancy outside marriage, text messages, hotel records or neighbor complaints. This means the law can become a tool not only of punishment but of family control and social intimidation.

The gender imbalance is one of the clearest patterns. The United Nations Working Group on discrimination against women and girls has warned that adultery laws often violate rights to privacy and equality because they are applied in ways that target women more aggressively than men. A woman may face criminal exposure because a pregnancy is visible. A man in the same affair may deny paternity or avoid scrutiny. In some systems, women also bear a heavier burden in divorce if adultery is alleged, especially where fault-based rules affect maintenance or child access. Even where the text of the law appears neutral, enforcement often is not.

The law also matters beyond criminal courts. In many countries, adultery remains a ground for fault-based divorce. That may sound outdated, but it still shapes real outcomes. In England and Wales, adultery used to be one of the formal facts cited to obtain a divorce before no-fault reform took effect in 2022. In many U.S. states, adultery can still influence alimony and property disputes, though the weight varies sharply by jurisdiction. In parts of Latin America, Europe and Asia, legal reforms have reduced the central role of fault, but family court judges may still consider marital misconduct indirectly when deciding money, housing or children’s living arrangements. What looks like a private betrayal can quickly become a legal lever.

That legal leverage can carry dangerous consequences. Scholars and rights groups have long argued that adultery laws do not protect families so much as invite coercion. Accusations can be used to pressure a spouse in custody fights, blackmail a partner into surrendering assets, or justify surveillance of phones and movement. In some countries, women who report sexual assault have themselves faced adultery charges if authorities believe they cannot prove lack of consent. That risk has been documented by international rights advocates in several legal systems where sex outside marriage remains criminalized. The effect is chilling. It discourages victims from seeking help and gives abusive partners another means of control.

There is also a hidden cross-border problem. People increasingly live, work, marry and divorce across different legal systems. An affair that carries no criminal risk in one country may expose someone to prosecution, detention or child-custody damage in another. Migrants, expatriates and international couples can be caught by rules they did not expect. Family law experts often warn that foreign residents in Gulf states, for example, may assume their home country’s norms apply to private life when they do not. Even where criminal laws have softened, immigration and family-status rules can still make intimate conduct legally costly. That mismatch between personal expectations and local law is becoming more important as cross-border families become more common.

Why do these laws endure? Part of the answer is political symbolism. Governments often defend adultery bans as necessary to protect morality, marriage or social order. But legal history shows they are also tied to older ideas about inheritance, legitimacy and male control over family lines. In colonial legal systems, adultery laws often reflected Victorian morality rather than local custom. In religious legal systems, lawmakers may frame reform as a challenge to tradition itself. That makes change harder, even when prosecutions are rare. A law can survive for decades simply because it sends a message, not because it solves a problem.

Evidence suggests it solves very little. Research on divorce and family stability generally points to economic stress, alcohol abuse, domestic violence and unequal care burdens as more powerful drivers of marital breakdown than criminal law. Countries that decriminalized adultery have not shown clear signs that prison threats preserve marriage. Instead, legal reform has tended to shift disputes into civil family law, where the state can focus on support, safety and children rather than punishment. India’s 2018 ruling reflected that logic directly. The court did not endorse infidelity. It said the criminal law was the wrong tool.

A better legal approach is emerging, though unevenly. Decriminalization is the first step, especially in systems where adultery can trigger arrest or corporal punishment. The second is divorce reform that reduces the incentive to weaponize allegations. No-fault divorce laws, stronger privacy protections, and clear limits on digital surveillance between spouses can all lower the temperature of family disputes. Courts also need better rules to ensure adultery claims do not undermine domestic violence reporting or become a shortcut to discriminate against women in custody cases. In international settings, governments could do more to warn travelers and foreign workers about local family-law risks that are often buried in fine print and rumor.

The deeper question is what the justice system is for. If the point of law is to prevent harm, protect rights and resolve disputes fairly, adultery laws often fail that test. They do not heal trust. They rarely protect children. They can deepen inequality and reward control. Around the world, lawmakers are slowly recognizing that intimate betrayal may be painful, but pain alone is not a sound basis for criminal punishment. Until that principle is applied more consistently, the legal meaning of an affair will still depend heavily on where a border falls, and on who is being judged when a marriage breaks down.