It wasn't popcorn reading per se, but in Japanese class during high school one year our sensei was going by rows to have us read the sentence and answer. I knew what my sentence would be ahead of time, but when it was my turn it didn't matter. The first word was "Midori" or "green" and for what felt like 10 seconds I was going "mmmmmmmmmm". I didn't hear any laughing or anything so that was good.