拉不出屎來怨茅房 [----来---]

Jyutping
Pinyin lā bù chū shǐ lái yuàn máo fáng

Definitions (CC-CEDICT)
  1. lit. to blame the toilet because one is having difficulty completing a bowel movement (idiom)
  2. fig. to blame others for problems caused by one's own shortcomings