若要人不知,除非己莫為 [ㄖㄨㄛˋ ㄧㄠˋ ㄖㄣˊ ㄅㄨˋ ㄓ , ㄔㄨˊ ㄈㄟ ㄐㄧˇ ㄇㄛˋ ㄨㄟˊ; ruo4 yao4 ren2 bu4 zhi1 , chu2 fei1 ji3 mo4 wei2] If you don't want anyone to know, don't do it (idiom). fig. If you do something bad, people will inevitably hear about it. ◄ ►