馬ば脚きゃくを現あらわす

expression, godan verb (-su)

reveal one's true nature; show one's true colors; give oneself away

Idiomatic expression meaning to unintentionally expose one's hidden character, intentions, or a lie. Often used when someone's pretense slips.

• 彼かれはうっかりして馬ば脚きゃくを現あらわした。

  He carelessly gave himself away.

• 嘘うそをついていると、いつか馬ば脚きゃくを現あらわすものだ。

  If you keep lying, you'll eventually be exposed.