watch your back
注意周围的威胁或危险，保护自己免受伤害。
口语·提醒小心提防
英文释义
to be cautious and wary of potential danger or betrayal
例句
In this business, you always have to watch your back.
典故来源
源于对潜在危险或背叛的警惕，常见于冒险或竞争环境。