when / while one's back is turned

/wɛn wˌaɪl wˈɒnz bˈak biː tˈɜːnd/

/wɛn wˌaɪl wˈʌnz bˈæk biː tˈɜːnd/

[phrase]

when / while one's back is turned

[PHRASE]

used of a situation in which one is preoccupied with something else or is not looking

What is the origin of the idiom "when one's back is turned" and when to use it?

The idiom "when one's back is turned" likely has its origin in the idea that when a person's back is turned, they are not able to see what is happening behind them. This lack of awareness can be exploited by others for various purposes, whether it's mischievous acts, pranks, or more serious actions. It is used to describe situations where something occurs or someone takes action when another person is not watching or aware of it.

Examples

1. The children were making faces at the teacher when her back was turned.

2. We won’t let them catch you while your back is turned.

3. I don’t know what these kids get up to when my back is turned.

4. Let me tell you, lipreading your teacher when their back is turned is very, very difficult.