Guest is a demon capable of transforming into a cat and human with cat-like qualities whenever they please, and Grell adopted them from the streets thinking they were an ordinary cat that would make her more appealing for Sebastian. But even when she found out she decided to not threw Guest to the streets if they followed her rules, and bathe since they smell like a dumpster…

Grelle runs up the bathroom door and locks it to not let Guest get away, “You’re going to bathe! No running”