My headcanon is that the people outside the classroom aren't there for just Saeki, but that they're well aware of the sleeping volcano of a romance... And they're hoping to catch a glimpse of some indications of ... Seismic activity?
I expected the kabedon to be countered with a counter-kabedon, but this is much better.
You'd have to be in a pretty cramped alleyway to pull that off.
Imagine doing a kabedon only to be countered by kabedon. But then you counter BACK with another kabedon, but she also counters back with a kabedon! While both of you are blushing exponentially, neither of you will back down and continue kabedoning until one of you does the ultimate kabedon move and forces the other one to admit defeat