without batting an eye

Related to without batting an eye: without blinking an eye, without batting an eyelash, batting an eyelash

without (even) batting an eye

Without having or displaying any sort of emotional response, especially to that which would normally elicit such a reaction. When we were traveling, Janet used to eat things like crickets and jellyfish without batting an eye. Be careful—guys like that will kill you without even batting an eye.
See also: batting, eye, without
Farlex Dictionary of Idioms.

without batting an eye

Lit. Fig. without showing alarm or response; without blinking an eye. I knew I had insulted her, and she turned to me and asked me to leave without batting an eye. Right in the middle of the speech—without batting an eye—the speaker walked off the stage.
See also: batting, eye, without
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

without batting an eye

Showing no emotion, acting as though nothing were unusual. For example, Richard ate the snails without batting an eye. A related phrase is not bat an eye, as in He didn't bat an eye when she told him he was being laid off. These expressions, which use bat in the sense of "blink," date from about 1900.
See also: batting, eye, without
The American Heritage® Dictionary of Idioms by Christine Ammer.

without batting an eye

Betraying no surprise or emotion, remarking nothing unusual. Batting here is an older word for “blinking,” but the term dates only from the turn of the twentieth century. O. Henry used it in Whirligigs (1910): “I’ve stood by you without batting an eye, in earthquakes, fires, and floods.”
See also: batting, eye, without
The Dictionary of Clichés by Christine Ammer
See also:
  • without (even) batting an eye
  • without (even) batting an eyelash
  • without (even) blinking an eye
  • without blinking an eye
  • heartstring
  • play on heartstrings
  • play on the/(one's) heartstrings
  • strike a chord
  • strike a chord (with someone)
  • strike/touch a chord
References in periodicals archive
How is it that some dogs deal with these stimuli without batting an eye, while others cower behind their owners with little or no apparent provocation?
Be brave: how to help your timid dog find courage
He writes checks that run into the thousands for machinery without batting an eye, yet some life insurance man comes along and offers him a paltry amount of insurance.
Show them worthwhile programs and speak the language they understand
Without batting an eye, Moinzadeh takes his shoes off and gives them to him."
No good deed unnoticed
She might not have X-ray vision or be able to leap over a building in a single bound, but TV and radio presenter Gabby Logan can manage to keep a pair of lively twins out of trouble, handle TV cameras and match reports without batting an eye and still look calm and relaxed at the end of it all.
GABBY THE SUPERMUM; OntheBox FINAL SCORE Saturdays, BBC1
Ward Fearn played it without batting an eye. In addition to Jim's marvelous playing, it's worth listening to the recording again with an ear to hearing Ward play third.
Correspondence
"Oh no dear," Edith replied, without batting an eye. "I don't inhale that far down." (Nurse's Calendar)
C humor
He took us on numerous hunts and loaned me expensive deer hunting rifles without batting an eye. In short, no teenage boy could have had a better or more ethical mentor, and no teenage boy could have been exposed to more hunting adventures that would later become etched in his memory forever.
One more season ..
They are killing hundreds of people without batting an eye While the rest of the world stands idly by In Gaza they're mourning a child blown up in their bed Whilst in Israel it seems barely a tear is shed
Palestine: A Fragment u Poems
Without batting an eye lid, he just said no and again went back to his conversation.
Holiday spoiled