have illicit relations with sb
It is a Chinese idiom, Pinyin is y ú Qi á ngzu à nxu é, which refers to cheating between men and women. From Mencius Teng Wengong II.
The origin of Idioms
It is said in Mencius Teng Wengong Xia: "if you don't wait for your parents' orders and the words of the matchmaker, you can see each other through the holes and follow each other beyond the wall, then your parents and Chinese people are cheap."
Analysis of Idioms
Jump over a wall and drill a hole
Idiom usage
It's hard to make sure that there's nothing wrong with my elder brother leaving a beautiful woman to live alone. A warning to the world by Feng Menglong in Ming Dynasty
have illicit relations with sb
a mad dog barking at the sun -- in the futility - kuáng quǎn fèi rì
prevent divulgence of one's secrets - shā rén miè kǒu
the melon is sweet , but the stalk is bitter - gān guā kǔ dì