Translation guide
The concept of infidelity in Japanese is expressed through various terms that differ in nuance, formality, and context. The most common general term is 浮気, but more formal or legal terms exist, as well as specific words for adultery.
To refer to a partner being unfaithful in a romantic or sexual relationship, often in a casual or emotional sense.
The most common and versatile word for infidelity or cheating. It can refer to a one-time fling or an ongoing affair, and is used in both casual and serious contexts. It implies a breach of trust in a romantic relationship.
彼氏が浮気をした。
My boyfriend cheated on me.
浮気は絶対に許さない。
I will never forgive infidelity.
Refers specifically to adultery or an extramarital affair. It carries a stronger moral and social condemnation than 浮気, and is often used in legal or formal contexts. It implies a sustained relationship outside of marriage.
不倫関係がバレて離婚した。
The affair was discovered and they got divorced.
不倫は社会的に許されない。
Adultery is socially unacceptable.
The verb phrase meaning 'to cheat' or 'to be unfaithful'. This is the most natural way to say someone is engaging in infidelity.
彼は彼女がいるのに浮気をしている。
He is cheating even though he has a girlfriend.
The verb phrase for committing adultery. Used when the unfaithful person is married.
既婚者が不倫をするのは問題だ。
It's a problem when married people commit adultery.
To describe infidelity specifically between unmarried partners, often with a nuance of a fling or casual cheating.
As above, 浮気 is the default term for cheating in any romantic relationship, including dating. It does not require marriage.
付き合ってるのに浮気された。
I was cheated on even though we were dating.
Literally 'two thighs', meaning two-timing or dating two people at the same time without their knowledge. It emphasizes the deception of maintaining multiple relationships simultaneously.
The person with whom one is cheating; the 'other woman/man'.
浮気相手は職場の同僚だった。
The person he was cheating with was a coworker.
To refer to infidelity in a legal, formal, or socially serious context, especially within marriage.
The standard term for adultery. It is used in news, legal discussions, and formal complaints. It implies a violation of marital vows.
不倫が原因で慰謝料を請求された。
They were sued for compensation due to the adultery.
A legal and archaic term for adultery. Rarely used in everyday conversation, but may appear in historical or legal texts.
Secret adultery or illicit intercourse, often with a historical or literary flavor. Implies clandestine meetings.
To describe a situation where a partner forms a deep emotional bond with someone else, which may not involve physical intimacy.
Literally 'heart's infidelity', this phrase specifically refers to emotional cheating. It is commonly understood in modern Japanese.
体の関係はなくても、心の浮気は許せない。
Even if there's no physical relationship, I can't forgive emotional infidelity.
A more formal way to say 'emotional infidelity', using 精神的 (mental/emotional).
精神的な浮気も浮気のうちだ。
Emotional cheating is still cheating.
浮気 (uwaki) is a broad term for cheating in any romantic relationship, including dating. It can be a one-time fling or an ongoing affair. 不倫 (furin) specifically refers to adultery within marriage and carries heavier social and legal implications. Use 浮気 for general cheating, and 不倫 when marriage is involved or when emphasizing the seriousness of the act.
彼氏の浮気が発覚した。
My boyfriend's cheating was discovered.
既婚者の不倫は離婚の原因になる。
Adultery by a married person can lead to divorce.
Using 不倫 when the person is not married can sound overly dramatic or incorrect. Stick to 浮気 for dating relationships.
彼に二股をかけられていた。
He was two-timing me.
姦通罪は廃止された。
The crime of adultery was abolished.
密通が露見して大騒ぎになった。
The secret affair was exposed and caused a huge uproar.