雙方都有責任;一個巴掌拍不響
it takes two to do sth
one person cannot be completely responsible for sth
You can't put all the blame on him. It takes two to make a marriage.你不能全責怪他,結婚是兩個人的事。
釋義來自《牛津高階英漢雙解詞典》第 9 版