give the game away
US /ɡɪv ðə ɡeɪm əˈweɪ/
UK /ɡɪv ðə ɡeɪm əˈweɪ/

1.
泄露秘密, 暴露真相
to reveal a secret or surprise, often unintentionally
:
•
Don't give the game away by telling her about the surprise party.
不要告诉她惊喜派对的事,以免泄露秘密。
•
His nervous laughter almost gave the game away.
他紧张的笑声差点泄露了秘密。