To Katie's horror, Tiff followed up her words by thrusting her hand deep into the empty, open balloon. On Katie's chest, her boobs pushed outward in identical, screamingly unnatural hand-shapes which mirror the current shape of the balloon.
"Oh, this is boss!" cried Tiffany, making her hand into a fist with a poking finger and prodding at the underside of Katie's rubbery nipples.
"Stop it, Tiffany!" yelled Katie, watching as her friend now did sign language within her chest. "That doesn't feel good!" Indeed it did not; having her rubber flesh stretched and poked made Katie feel slightly nauseous; she felt like she herself was being stretched like rubber.
"What? This is awe-" Tiffany began, but before the "som" came out both of Tiffany's breasts popped. Just as a balloon might, so did her chest break open with a loud POP, sending small fragments of rubber boob and leaving the rest to dangle in torn shards from the edges of two large holes in her torso - through which were poking identical copies of Tiffany's right hand, their purple nails dangling in front of Tiffany's eyes as if advertising the product.
Katie looked down, eyes wide like a startled deer's, and Tiff took the opportunity to examine the balloon. It too had popped, but her hand disappeared beyond it's ring! She looked up, afraid, and tried to wiggle her fingers. The fingers extruding from her cursed pal - both sets of them - wiggled in response. Well, at least she hadn't lost her hand.
Just then Katie's shock wore off, and she dropped into a dead faint. Tiff rushed forward but could not catch her in time; Katie's head made a nasty crack on the tiled floor as her body dropped like a rag.
"Katie! KATIE!!!" Tiffany screamed as she knelt beside her friend. "Oh, Katie, PLEASE wake up. PLEASE! You have to be awake for us to continue the Transform or Dare and fix you! Oh Katie - " Tiffany tried to stroke her beleaguered friend's forehead with her right hand, but came up against the stump of arm that marked where the balloon hung on her. She the thing off (luckily it was still a ring; had she tore it into a string they would have been in REAL trouble) and hurled it blindly away; as she did, she saw the hands retreat into her friend's chest, and realized that they (or at least one of them) was back on her wrist. Then her eye was caught by something else in those broken holes - or, rather, the absence of something else.
The floor of the locker room was tiled in alternating squares of white and burgundy. As Tiffany looked into the gouges in her friend's body, however, she did not see the pattern of the floor. Nor did she see the raw and bloody flesh that was Katie's insides, as Tiffany had expected to. Instead, beyond the lip of rubbery flesh was - the ceiling.
Tiffany stared, uncomprehending, then started up. She looked around wildly for the discarded balloon, and found it a few feet away resting on the floor. She raced to it, slipping on the floor and not caring, then crashed down by it and saw that through it's hole too she saw the ceiling. It was like looking into a window, or a mirror that only showed what was behind you. But Tiffany had a feeling it was more the former than the latter.
Tentatively, she stuck a finger into the balloon - and saw it come out in duplicate from Katie. Then she raced over to Katie, put a finger into her breast-cavities, and saw it emerge from the balloon. They were linked! Like . . . like a teleportation gateway!
Tiffany was hopping up and down with excitement before she realized that she had forgotten about her injured friend. Hell, Katie was now moaning, and Tiffany had been too wrapped up in SCIENCE to realize it! What was wrong with her?
"Katie?" she asked gently. "Katie, are you there? Are you awake?"
"yes..." Katie replied weakly. "but...oh, my head, it hurts. Baaaaaaad."
"I know." Tiffany said, and realized her voice was a touch impatient. Oh well, she had a right to be. "Katie, you have to use up your turn so I can transform you back."
"What?" Katie said, sounding somehow distant. "My head, it feels like its being pulled in two, no, a million different directions. Something's wrong, aaaaaaah..."
"Katie!!" Tiff said, and snapped her fingers loudly in front of her friend's eyes. This seemed, to Tiff's immense relief, to finally get Katie's attention. "Use up your turn so I can transform you back!"
"Transform or dare." Katie said.
"Dare." Tiff replied with hesitation.
"I dare you to snap your finger in the next second."
Tiff snapped her finger immediately, then asked the magic question again.
"Transform" replied Katie. Her face was looking paler now, and she could feel the pain in her head building. She wasn't going to be able to ignore it for long.
"You will turn back into your normal self immediately, and stay that way until I transform you again."
Paradoxes of time and space are pernicious, destructive little things, and the doubling effect of Katie's burst breasts (by creating two hands from one, it had performed the impossible and created new matter where none existed) had been a very nasty one indeed. Katie's pain was from the terrible strain that the cold fusion of every breeze passing through the balloon was putting on reality, and had it gone on much longer, Tiffany would have felt it too. The girls would figure this out later, but for now, the young singularity was overcome by the vast power of the Transform or Dare curse, and as Katie's breasts closed over with flesh - real, not rubber, and flat as a pancake - the girls were rescued from the brink of oblivion.
"Shall we go to gym?" Tiff asked without much enthusiasm.
"Yeah." Katie said, her voice shaky. She picked up her gym top and put it on, savoring the touch of her normal breasts. "Yeah, I guess we have to."
They didn't say much else for the rest of the school day.