You get caught perving on your big step-sister as she's in the middle of getting ready for her night out. She tells you to leave or she'll tell your parents, but you've got other plans. You're obsessed with her curves and you just want to see more. Much more. So you use your new growth device on her, causing her body to suddenly and rapidly expand. Everything about her begins growing and your step-sister panics and begs you to make it stop as her curves burst through her t-shirt, her pantyhose and nearly the ceiling! But when the growth stops, the tables turn as your big step-sister realises her size and the power it now gives her...