知らぬは亭主ばかりなり、知らぬは亭主許り也
しらぬはていしゅばかりなり
shiranuhateishubakarinari
JMdict entry #2418970
- expressions (phrases, clauses, etc.) idiomatic expression the husband is always the last to know; everyone knows of the wife's infidelity but the cuckolded husband