一家人不说两家话
Traditional (Taiwan):
一家人不說兩家話
-
lit. family members speak frankly with one another, not courteously, as if they were from two different families (idiom)
-
fig. people don't need to be deferential when they ask a family member for help
-
people from the same family should stick together (and good friends likewise)
Character by character
Sources