joined at the hip是一个常见的短语，它的意思是：交情极厚的、死党。

【例句】
Whenever you see Sarah, you know Lucy isn't far away-they're joined at the hip, those two!
你一看到莎拉，就知道露西肯定在不远的地方，她们俩真是死党！

We grew up together and we were alwaysjoined at the hip.
我们一起长大，我们的关系非常好。