Your stepsister invited you over to do some hot yoga with her. It sounds like a total drag but she is pretty hot and you like when she wears those skimpy spandex shorts. When you arrive she hands you this strange looking shake. She tells you that its a super healthy drinkrecipe she found on the internet. You gulp it down but it tastes even worse then it looks. It leaves this weird coating in your mouth which causes your tongue to tingle. As you turn to her, you notice something really strange happening. Normally your the same height as your step-sister but it looks like she's gotten taller! Your skin starts feeling this tingly sensation you felt on your tongue and then your step-sister grows even taller! She now towers over you and claps her hands together and giggles. She explains that shake you had was really a shrinking powder she got on the intent! You look down and to your horror you realize its not her getting taller but you who's shrinking! She picks you up and you are now so small you fit right into her hands! You scream and yell at her, begging for her to turn you back to normal size! She laughs and ignores your pleas, "I told you that we were going to do yoga and we still are! The only difference is now that you will being doing it under my control! I'm going to be doing my stretch's on top of you, I hope I don't s q u a s h or s m other you with my butt! Maybe I'll even tuck you in my shorts! Haha, I see the way you check my ass out, now you get to see what its like to be trapped deep between my humongous ass cheeks! Hahaaha"