We were in our tuition class in the twelfth standard, and the good looking young chap who taught a few chapters of Math was busy writing down sums on the small, blackboard. Soft spoken and shy, he slowly was explaining the theorems when this donkey outside suddenly went heeee-haaaaw. It was so loud and funny as if the donkey were having fits of laughter. I think he was desperately trying to make us laugh. We were so stressed out trying to solve math.
We girls couldn't control our giggles. Sir was serious. He continued concentrating on his work though he knew we were shaking so hard. So we couldn't even burst out laughing.
It was such a monumental effort just preventing ourselves from breaking out into a loud guffaw just like the impetuous donkey.