keep (someone's) unmentionables under wraps

Traducciones
держать (чьи-то) неприличные вещи в секрете
He managed to keep his unmentionables under wraps despite the rumors.
Ему удалось держать свои неприличные вещи в секрете, несмотря на слухи.
Definiciones
To keep someone's underwear or private matters hidden or secret; often used humorously to refer to maintaining privacy about personal or sensitive topics.