ボロを ぼろをだ
borō dasu

Godan Verb (su)
Expression

1. to expose one's faults; to have one's defects exposed; to show oneself up

あいつでかいことばかり ってるけど、そのうちぼろを すよ。
aitsu dekai kotobakari itterukedo sonōchi borō dasuyo.
He's always talking like a big shot, but it won't be long before all his faults are exposed.
Other forms: