马脚

mǎjiǎo

马脚 — mǎjiǎo

1. a flaw or clue that exposes what one wishes to hide; a tell (lit. 'horse's foot')

   他说话时露出了马脚，大家这才明白真相。 tā shuōhuà shí lùchū le mǎjiǎo dàjiā zhè cái míngbái zhēnxiàng — He let his tell slip in his speech, and only then did everyone understand the truth.