When one is very desperate to use the toilet in order to shit, but it is already occupied. This is the agonised dance performed, hopping from one leg to the other, going "oooo oooo owwww oooww oooo!" and pulling a grotesque face. Like an angry chimp in a zoo.
Dude 1: "My new chick spends hours in the bathroom doing her face. I'm left outside doing the chimp dance every morning!"
Dude 2: "Bad shit, my man!"