You mean you wouldn't want me talk about how the warmth of Twilight slowing going Rarity's mouth. She wants to try out the goo spell that she came up with, there were notes she came across that told her it would causes desired effects to whom ever she entered and that person is Rarity.

Rarity could feel her belly begin to move past her belt, like jello sliding of the edge of a table. Gravity was is full effect, and her belly was more like a soft apron at this point. She made a way for the mirror to see what Twilight has done, talking was useless because she can't talk with a mouth full of Twigoo. Walking to the mirror caused her to realize how fat her belly had become -- each step akin to a yo-yo as it bounced down then back up again an in exaggerated motion.

Once in the mirror she could see her beach ball-esque pushing up against her breasts. Her bust was splitting button on her suit and cleavage was overflowing from the top and between each opening her large tits could find. She moved to hold it together but a silly action nonetheless as all her buttons gave way and her bra was starting to peek out as well.

She turned around and her belly swung and almost took her with it. Regaining her balance she not only caught sight of her pants splitting at the seams, but at her ass rising out of her pants like a baked treat in the oven. She reached back and took a hold of her ass, savoring the large wobbling flesh. Her other hand slapped her belly, seeing it oscillating as each wave of fat slowly returned to its stable state and her large pendulum came to a stop.

The once skinny woman was now replaced with a large sexy beast and she love every ounce of her new body; from the mass of her bean bag like belly that hung near her knees to her prodigious ass that was shredding her pants apart and not to be forgotten was her  large bust that made short work of her outfit.Lowering her self down to her knees she wiggle and toyed with her belly; she noticed she stopped growing and that Twilight was all in her stomach at noted by the taut feeling  under the foam like softness of her gut.

Twilight told Rarity that she need to get out now and take notes at her new discovery. However Rarity wouldn't just let a meal like that go, she love the effect and wanted it to stay. Twigoo's pleas to her friend fell on deaf ears; enamored to a point of some kind of trance she let her hands roam her new bigness.