take the secret to the grave
take a/the secret to (one's)/the grave
To not reveal a secret for the duration of one's life. I can't believe that grandma took such a huge family secret to her grave! If Uncle Joe hadn't blurted it out, we'd never have known about it! Oh, Emily is a loyal friend—she would definitely take the secret to the grave.
Farlex Dictionary of Idioms. © 2022 Farlex, Inc, all rights reserved.
take the (or your etc.) secret to the gravedie without revealing a secret.
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