The idiom the pot calling the kettle black means that someone is criticizing someone for something that both of them do, without realising it. It is a way of pointing out hypocrisy.
A pot and a kettle on the stove are both blackened equally from use.
A pot and a kettle on the stove are both blackened equally from use.
You can't complain that I'm late when you are always late yourself. That's like the pot calling the kettle black.