So imagine, if you will, the following scene.

Cristina, running bathwater, while telling the girls to undress for the bath.  Cristina, going to get a clean washcloth.  Cristina, returning to the hallway, and seeing the following:

Arden, completely naked, in downward dog position (hands and feet down, rump in the air).  Lily, completely naked, with her face nearly UP Arden’s rear end, sniffing away and cacking gleefully, while Arden screams, “My BOTTOM STINKS!!!” 

The two of them. They are seriously insane.