屎坑公賣草紙 (si2 haang1 gung1 maai6 cou2 zi2) — to be honest with oneself; to just trust someone to be honest and do the right thing even if others are not looking [colloquial] in Cantonese
siˊ²屎haangˉ¹坑gungˉ¹公maaiˍ₆賣couˊ²草ziˊ²紙简 屎坑公卖草纸
Mandarin Pinyin: shi3 keng1 gong1 mai4 cao3zhi3
Meaning of 屎坑公賣草紙
nounto be honest with oneself; to just trust someone to be honest and do the right thing even if others are not looking [colloquial]