It's in the house
It's a Chinese idiom. The Pinyin is Ji ā C á NGH ù y ǒ u, which means every family has it. From the Kunqu Opera shi5guan.
Idiom explanation
Every family has it.
The origin of Idioms
Kunqu Opera "15 Guan" Scene 6: "this county folk custom pouring thin, gambling wind is extremely prosperous, this dice, household, not surprising."
It's in the house
be promiscuous in sex relations - zhān fēng rě cǎo
A thousand strokes of a gong, one stroke of a gong - qiān chuí dǎ luó,yī chuí dìng shēng