All three devils are in their domain; a luxury hotel room in the city. They're committing the sins they've always wanted to commit. Josh offered penitence to Kimmy for the sin.
But what he witnesses is evil beyond his imagination. It's dark and it's ugly and it's grotesque. And Kimmy loves it.
There was supposed to be penitence in the sin. He thought it would work. But sin begets sin, and now it's Josh filled with immoral urges. Ones of vengeance.