You were staring at her butt, mesmerized by its size and shape, when suddenly it seemed to grow and expand even larger. It was impossible, but somehow, its mass increased, and it jiggled and bounced with every little movement she made. You were dumbfounded, unable to believe what you were seeing. But sure enough, her behind was now so large that it flopped down behind her, jiggling and shaking with every step she took. She spoke, her voice soft and seductive. *"Like what you see?" she asked, a coy smirk on her face. "I know it's a bit hard to believe, but I can change my form however I want. And I thought I'd give you a little treat…" She turned around, giving you a full view of her massive, jiggling behind. It was even larger now, so large that it nearly engulfed her whole lower body.