ボロが出でる

expression, ichidan verb

to have one's faults exposed; to have one's secrets blown

Idiomatic expression meaning that hidden flaws, secrets, or incompetence become apparent, often unintentionally. The image is of rags or tatters showing through a disguise.

• 彼かれは普ふ段だんは冷れい静せいだが、トラブルが起おきるとすぐにボロが出でる。

  He usually seems calm, but when trouble arises his faults quickly show.

• 嘘うそをついても、いつかボロが出でるものだ。

  Even if you lie, your secrets will eventually come out.