An idiom meaning to criticize someone else for a fault that you also have (the pot calling the kettle black).
彼が遅刻を注意したが、彼も昨日同じことをした。目くそ鼻くそを笑うとはこのことだ。
He scolded someone for being late, but he was late yesterday too. That's the pot calling the kettle black.
あなたが人の失敗を責めるべきじゃない。目くそ鼻くそを笑うようなものだよ。
You shouldn't blame others for their mistakes. That's like the pot calling the kettle black.
双方ともミスをしているのに一方だけを非難するのは目くそ鼻くそを笑う行為だ。
When both sides made mistakes but only one is criticized, that's the pot calling the kettle black.