keep a straight face
面無表情;保持嚴肅的表情
口語·描述忍住笑或保持嚴肅
英文釋義
to maintain a serious or composed expression, especially in a humorous or difficult situation
例句
It was so funny, but I managed to keep a straight face.
典故來源
源自戲劇表演中保持面無表情以掩飾真實情緒,straight face即無表情的臉。