I found this aphorism in my book of Korean aphorisms.
눈도 깜짝 안한다 nun.do kkam.jjak an.han.da eye-TOO blink NOT-do-PRES The eyes don't even blink.
This means a person doesn’t blink in the face of danger or surprise. Actually, the English expression is identical: “He didn’t even blink.”
My friend Seungbae, on reading some of this here blog, sent me an expression to include in my Korean expressions (which I’ve been doing weekly), but I didn’t include it this week because it’s been a bit hard for me to figure out. I need to do some more research. It’s not really an aphorism, more like a contemporary slang expression. Maybe next week.