give the game away

US /ɡɪv ðə ɡeɪm əˈweɪ/
UK /ɡɪv ðə ɡeɪm əˈweɪ/
"give the game away" picture
1.

rovinare la sorpresa, svelare il segreto

to reveal a secret or surprise, often unintentionally

:
Don't give the game away by telling her about the surprise party.
Non rovinare la sorpresa dicendole della festa a sorpresa.
His nervous laughter almost gave the game away.
La sua risata nervosa ha quasi rovinato la sorpresa.