up to no good
打什么壞主意
口語·懷疑某人做壞事
英文釋義
engaging in or planning something bad or suspicious
例句
The kids are being too quiet—they must be up to no good.
典故來源
源自16世紀英語，直譯為“在干壞事”，強調可疑或不良意圖。