As she stood there gazing in complete disbelief at her circumstances, Princess Celestia could only watch as her body continued to expand slowly, the ever present hissing from within her, steadily increasing in nose and volume. She attempted to cast as many powerful spells to counteract her bloating, but nothing seemed to work. Her regal dress, torn and burst almost apart from her now covering her swollen boobs, the size of large beach balls, slowly tearing the fabric apart much to her shame and embarrassment. Her regal gloves, already splitting at the seams, would not hold much longer as her arms, hopelessly being pushed further apart from her near spherical body, pushed against her tightening amulets. Furthermore, her neckless pushed deep into her swelling neck and her puffy cheeks, making ominous groans as the gold struggled to hold together. Her leggings, long since split apart from her bulking legs and her belt, long since snapped away from her gigantic swelling body, lay before her, hidden beneath her belly and long since from her normal view, not that she could see anything beneath her as her cheeks nearly covered her face too at this point. All the more reason why in a strange way, it was a small miracle that she couldn't see beneath her body as her royal underwear had long since snapped away, though she could only pray mentally that no one would come into her quarters to see her bare, bloated behind. All she could do, aside from peer between herself, and the mirror she gazed at, was to still wonder to herself,"Why is this happening to me? I'm blowing up like a balloon and nothing is stopping it! Am I going to explode? Am I going to stop? What is going on?!"

A follow-up to this gem; https://derpibooru.org/images/2734168