Definition and pronunciation
extramarital sex — sexual activity that occurs outside a marriage when at least one person is married to someone else.
Pronunciation: /ˌɛkstrəˈmærɪtəl sɛks/.
Easy explanation
Extramarital sex means a married person has sex with someone who is not their spouse. People often use it in news, law, and counseling to describe affairs without judging the people involved.
Part of speech and grammar
- Noun phrase (usually uncountable): extramarital sex; allegations of extramarital sex.
- Related forms: extramarital (adjective: extramarital affair), adultery (legal/moral term), affair (relationship term).
- Verbs around it: engage in / have / deny / admit extramarital sex.
Register and tone
Neutral-to-formal. Common in journalism, legal filings, and health writing. Compared with adultery, it sounds less moralizing.
Connection to sexuality
Direct. It names consensual sexual activity outside marriage. It does not cover non-consensual acts; those should be named specifically (e.g., sexual assault). In open marriages, agreed outside sex is usually not called extramarital within that couple’s rules.
Common collocations
extramarital affair; extramarital relationship; engage in extramarital sex; alleged extramarital sex; extramarital partner; evidence of extramarital conduct; scandal over extramarital sex.
Idioms and expressions
Not true idioms. Set phrases you’ll see: caught in an extramarital affair; accused of extramarital relations (older/legal).
Prepositions and nuance
- with — names the other person: extramarital sex with a coworker.
- during — timing: during the separation.
- outside — clarifies boundary: sex outside marriage.
- under — links to rules: impermissible under the code of conduct.
- against — rhetorical emphasis on vows: acts against marital vows (formal or moral tone).
Meaning stays the same; prepositions just anchor context (who, when, under which rules).
Word comparisons
- extramarital sex vs adultery — adultery can carry legal/moral weight; extramarital sex is descriptive.
- extramarital sex vs infidelity — infidelity can be sexual or emotional; extramarital sex is specifically sexual.
- extramarital sex vs affair — affair implies an ongoing romantic/sexual relationship; extramarital sex could be one-time or ongoing.
- extramarital sex vs open marriage — agreed outside sex in an open marriage is not a breach; many avoid calling it extramarital in that context.
- extramarital sex vs premarital sex — premarital involves unmarried people; extramarital involves at least one married person.
Real-life examples
- The petition cited extramarital sex as grounds for divorce.
- Reporters wrote “alleged extramarital relationship” until documents were confirmed.
- In counseling, the couple discussed boundaries and the difference between open agreements and extramarital sex.
- A workplace policy disciplined undisclosed relationships when they created conflicts of interest.
Sample sentences
- The article distinguished extramarital sex from non-consensual offenses.
- She denied having extramarital sex and requested privacy.
- He admitted to an extramarital affair and apologized to his family.
- Their open-marriage agreement meant outside sex wasn’t considered extramarital within their rules.
- Legal standards for divorce still reference extramarital conduct in some places.
Synonyms
adulterous sex, sex outside marriage, extramarital relations, extramarital affair, illicit relationship, cheating, unfaithful conduct, two-timing (informal)
Antonyms
marital sex, fidelity, faithfulness, monogamy, exclusivity, chastity, celibacy
Related terms
adultery, adulterous, adulterer/adulteress, infidelity, affair, open marriage, consensual non-monogamy, separation, divorce, reconciliation, marital vows, consent, capacity
Notes and etiquette
Use clear, nonjudgmental language. If the issue is consent or power imbalance, say so directly. If partners have explicit agreements that allow outside relationships, avoid labeling those relationships as extramarital in a way that implies wrongdoing.
Sexopedia.co is an educational glossary of sexual and gender-related terms—helping you improve your English while deepening your understanding of identity, language, and self-expression.