joined at the hip
紧密结合或密切相关
口语·形容形影不离
英文释义
extremely close or inseparable
例句
Those two are joined at the hip; you never see one without the other.
典故来源
源自解剖学概念，指连体双胞胎身体相连，后比喻两人关系极其亲密。