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

1.
entregar o jogo, revelar o segredo
to reveal a secret or surprise, often unintentionally
:
•
Don't give the game away by telling her about the surprise party.
Não estrague a surpresa contando a ela sobre a festa surpresa.
•
His nervous laughter almost gave the game away.
O riso nervoso dele quase entregou o jogo.