To tell tales out of school.
More Japanese Proverbs:
He who talks to a silent listener will soon stand naked.Japanese
A dying man discovers the honesty with which he was born.
Japanese
The child who died too soon was always beautiful and intelligent.
Japanese
When you have children yourself, you begin to understand what you owe your parents.
Japanese
Fortune will call at the smiling gate.
Japanese
When you are looking upwards you see no frontiers.
Japanese