She discovered her husband had a mistress and decided to divorce.
Tips
usage
情妇 specifically refers to a female extramarital lover. The male equivalent is 情夫 (qíngfū). The colloquial slang term is 小三 (xiǎosān, literally 'little third'), which is gender-neutral.
register
情妇 is a neutral descriptive term, not inherently vulgar. However, 小三 is more informal and carries a judgmental tone.
