A coala went to a local cathouse (a brothel or bordello).
Hired a girl for doing his business.
Afterwards coala was going to the door, when the working girl (a prostitute) took a dictionary under her bed and showed the meaning of a prostitute.
’Prostitute: a girl who do the works and get paid.’
Coala browsed some pages and finally showed the page: ’Coala: eats bush and leaves.’