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Detective Column

This column is the English version of a column written in Japan.

Disclaimer
This column was originally written in Japanese and has been translated into English for your convenience. Please note that the legal information and references discussed here apply specifically to Japanese laws and regulations. If you require legal advice or information relevant to your own country, we recommend consulting a qualified professional who is knowledgeable about the laws in your area.

Where Does Infidelity Begin? Defining Adultery and How to Confirm It

When married couples engage in romantic relationships outside their marriage, it’s considered “adultery” or “unfaithfulness,” subjecting them to possible compensation payments or divorce. You likely understand that infidelity is off-limits, but where exactly does adultery start?

In this article, we’ll clarify the line between infidelity and innocent relationships, explain the difference between “affairs” and “infidelity,” and discuss how to confirm adultery. If you’re worried about your partner’s possible affair, use this information as a guide.

The Difference Between Infidelity and Cheating

First, let’s clarify the difference between “infidelity” and “cheating.” These words often appear interchangeably, but they’re not identical.

Infidelity: Unfaithful acts between married individuals—“adultery.”
Cheating: Unfaithful acts in unmarried (dating) couples.

For unmarried couples, cheating causes no legal ramifications—if you can’t forgive your partner, you just break up. But for married couples, a legal and social bond exists. If one spouse cheats, the other can demand compensation or pursue divorce.

Unlike cheating, which has no legal definition and depends on personal boundaries (“holding hands is cheating,” “spending time alone with someone is cheating”), infidelity has a clear, legal standard. Keep this in mind.

Where Does Infidelity Begin? Defining Adultery

So, what’s the exact threshold for adultery? It’s not just whenever a spouse feels upset. Let’s look at the standard criteria.

Adultery Requires Physical Relations

Simply put, having sexual relations with someone other than your spouse is considered adultery. Rumors, emotional attachments, or even holding hands and kissing don’t meet the legal threshold for infidelity. However, even if there was no intercourse but forms of petting or sexual activity occurred, it counts as adultery.

Even Without Love, It Can Be Infidelity

Visiting adult entertainment venues or paying for sexual services may also be considered adultery, even if there’s no emotional connection. Many spouses resent these acts, and courts can regard them as forms of infidelity depending on the circumstances.

Cases Where Adultery Doesn’t Lead to Compensation

Sometimes, even with a sexual relationship, certain scenarios prevent compensation claims from the betrayed spouse.

If the Third Party Didn’t Know About the Marriage

If the unfaithful spouse hid their marital status, the lover may not owe compensation because they were deceived. Without knowing the partner was married, the lover can’t be held responsible in the same way.

However, courts will consider if the lover had opportunities to realize the person was married, such as working together or seeing a wedding ring.

If the Other Party Lacked Intent or Responsibility

If someone was coerced or forced into a sexual relationship with a married person, or if it was a one-sided pursuit, it might not be recognized as infidelity in terms of legal liability. Both parties must knowingly engage in the affair for it to count as adultery.

How to Confirm Adultery

Investigating on Your Own

Without proof, disputes over “cheating” often become endless. You might try checking your partner’s phone, belongings, or suspicious behaviors. While these measures might raise suspicions, they rarely provide definitive evidence. Use such clues to decide whether to seek professional help.

Hiring a Detective or Investigation Agency

If you want to pursue divorce, compensation, or confront your spouse’s lover, consider hiring a private investigator. Professional “infidelity investigations” can quickly and accurately gather solid evidence. Such reports are useful not only in out-of-court settlements but also in mediation or court proceedings.

Although it costs money and may feel daunting, many agencies offer free consultations. If you’ve been agonizing over suspicions or facing prolonged uncertainty, professional assistance can lead to a swift resolution and peace of mind.

By understanding what constitutes infidelity, you can better decide if your partner has crossed that line and whether it’s time to seek help.

Japanese Detective Column