大年初一吃饺子，没外人

大年初一吃饺子，没外人

Literally means:

no stranger or outsider is present at the traditional family meal

Actually means:

According to Chinese tradition, all the family members gather together to eat Jiaozi on the first day of the Lunar New Year. This phrase figuratively means that all present know each other well and are close to each other. It is often used to comfort people or to make them feel at ease in telling the truth.

中国的传统习俗，大年初一，全家人要聚在一起吃饺子。比喻都是关系亲近、彼此了解的自己人，没有不熟悉的人。