[PurveyorOfFineDares]

1 new rule for Tori: You must work out naked in your apartment for 1 hour total every week (can do all at once or split into 2-3 workouts). Kat can watch if she wants.

Ways you could modify this, pick any you like:
If your vibrator can be inserted or worn, you must have it on during the workout
If Kat decides to watch, Tori can demand that Kat eat Tori's pussy after the workout (or pick another forfeit if you don't like this one).
If Kat decides to join in and also do the naked workout, and manages to follow along with Tori successfully for the whole workout, Kat can demand that Tori eat Kat's pussy after the workout (or pick another forfeit if you don't like this one)