一个巴掌拍不响 (Yí gè bāzhang pāi bù xiǎng)

Meaning: A quarrel always involves two sides.

Literally: One palm alone can't clap

Example: “你们俩吵架，一个巴掌拍不响，都有责任。” — You two are quarreling, and it takes two to tango: you're both to blame.

Equivalents in English, French, Spanish, Japanese, German, and 2 more languages

English: It takes two to tango
French: Il faut être deux pour danser le tango (literally: It takes two to dance the tango)
Spanish: Dos no pelean si uno no quiere (literally: Two don't fight if one doesn't want to)
Japanese: 喧嘩両成敗 (Kenka ryōseibai) (literally: In a quarrel, both sides are punished)
German: Zum Streiten gehören immer zwei (literally: It always takes two to quarrel)
Portuguese: Quando um não quer, dois não brigam (literally: When one doesn't want to, two don't fight)
Dutch: Als er twee kijven, hebben ze beide schuld (literally: When two quarrel, both are to blame)