Olivia strives to be a good girl for Sosha, doing whatever Sosha asks, even when Sosha asks her to pee in her diaper.

In this scene we find Olivia wearing a diaper and snuggling with Sosha.  Sosha asks Olivia to pee herself.  At first, Olivia is reluctant, but wanting to be a good girl for Sosha she eventually gives in and wets her diaper.  This turns Sosha on, who then proceeds to go down on Olivia as a reward for doing what she was told.