谁人背后无人说谁人背后不说人
[shéi rén bèi hòu wú rén shuō shéi rén bèi hòu bù shuō rén]
This idiom roughly translates to 'Everyone has someone speaking behind their back, but everyone also talks about others behind their backs.' This phrase recognizes that humans often engage in gossip and criticizes this habit, indicating both sides are equally at fault when talking negatively about others.