Today, when I was teaching "Let It Be" to my high schoolers, I asked a teacher to translate the phrase "let it be" into Japanese. He then said the phrase in katakana English and waited for me to proceed with the lesson. I looked at him in bewilderment and said "No, in Japanese please", to which he replied "hakuna matata!". I lost the struggle to maintain composure, unsuccessfully trying to contain frustruated laughter as I asked him again. He answered "se la vie". Smack! Not that I was being melodramatic, it was a parasympathetic response that caused my hand to slap my forehead with such force. And that's pretty much how that lesson went for that particular class.
You should have slaped him instead.
That's priceless. I wonder how he is at charades?
hoppottoke, sawaruna, ijikuruna or even kinisuruna comes to mind.