Gym Instructor's Embarrassing Class

Description: Gym instructor essie is leading a keep fit class. but someone at the back of the class is playing around on the phone - and it looks like they have some sort of app that makes things disappear - namely essie's clothes.  as her clothing vanishes item by item, essie is torn between embarrassment and a desire to finish leading the gym class. but how will she react when the trouble maker waves her own missing clothes in front of her?