Arthur tries counting the number of doors so he can go to the bathroom...
...but he miscounts, and heads into the girl's bathroom.
Arthur is shocked to hear Francine's voice.
Francine and Muffy are shocked to see Arthur step into the wrong bathroom.
Arthur and Francine directly shout at each other, "What are you doing in here?!"
The whole school looks at Arthur in anger for what he did.
Arthur gets embarrassed for miscounting.