someone's back is turned

(one's) back is turned

One is not looking; one is distracted, absent, or involved in something else. Jimmy grabbed another cookie when his mom's back was turned. It turned out that the vice president of the company had been orchestrating a hostile takeover when the president's back was turned.
See also: back, turn
Farlex Dictionary of Idioms.

someone's back is turned

someone's attention is elsewhere.
1989 Orson Scott Card Prentice Alvin That prentice of yours look strong enough to dig it hisself, if he doesn't lazy off and sleep when your back is turned.
See also: back, turn
Farlex Partner Idioms Dictionary
See also:
  • (one's) back is turned
  • it's as well
  • (it's) just as well (that) (something happened)
  • turn onto
  • turn onto (someone or something)
  • turn onto someone/something
  • a little (bit) (too) rich for (one's) blood
  • too rich for (one's) blood
  • too rich for blood
  • too rich for someone’s blood