Turned her back on me

[Stephan]

Test No. incompl/inter-34 "Story (3)", answer 6

Sadly Doris had already turned her back on me and gone back to the kitchen.

Correct answer: (c) on

Your answer was: incorrect
Sadly Doris had already turned her back out me and gone back to the kitchen.

Hello Alan! Please explain me: Why is the phrase "her back on me..." correct? To my mind is "her back out..." true.
Best wishes.
Stephan, Europe

[Alan]

Hi,

Thanks for your message. Unfortunately there is no logic to idioms and this is an idiom. Turn your back on someone is to turn your back so that your back is facing them and this means that you walk away from them or ignore them. I'm afraid your suggestion of 'out' doesn't work.

Alan
_________________
English as a Second Language
You can read my ESL story In Order

[Stephan]

Thank you very much for your explanation, Alan!
Your tests are very useful and help me in my schoolwork.