/ˈɛkstrə ˈmærɪtəl rɪˈleɪʃənʃɪp/ – Phrase
Definition: mối quan hệ ngoài hôn nhân, mối quan hệ ngoại tình.
A more thorough explanation: An extra-marital relationship refers to a romantic or sexual relationship between a married person and someone who is not their spouse.
Example: The court found evidence of an extra-marital relationship between the defendant and a co-worker, which ultimately led to the breakdown of the marriage.