blow someone's cover

US /bloʊ ˈsʌm.wʌnz ˈkʌv.ər/
UK /bloʊ ˈsʌm.wʌnz ˈkʌv.ər/
"blow someone's cover" picture
1.

正体をばらす, 秘密を漏らす

to reveal someone's true identity or secret activity, especially when they are trying to keep it hidden

:
The spy's partner accidentally blew his cover by calling him by his real name in public.
スパイのパートナーは、公衆の面前で本名で呼んだことで、誤って彼の正体をばらしてしまった
She tried to keep her new job a secret, but her excited friend blew her cover on social media.
彼女は新しい仕事を秘密にしようとしたが、興奮した友人がソーシャルメディアで彼女の秘密をばらしてしまった