Sofia opened the house's door, tired after a lengthy soccer training session: she was still wearing her training clothes, shorts and a T-shirt that barely covered her ample bosom, with soccer shoes and socks completing her petite yet athletic figure.

"Dad and mom are out, and I already took care of Carla earlier," she thought, laughing to herself, "so tonight I have the house all to myself..."

She didn't even have time to finish the thought when...

SPLAT!!!

A frying pan descended mercilessly onto the girl's head, quickly compressing her body, which disappeared beneath the kitchen utensil. The pan in question was held by another girl, similar to Sofia but taller: she was wearing comfortable home clothes (which at the moment looked a bit wrinkled) and was barefoot; another substantial difference from Sofia was the lack of two important "assets" on her chest.

"Welcome back, little sister!" said Carla, Sofia's older sister, lifting the pan from the ground. On the ground, Sofia had been reduced to a shape resembling a coin, with a diameter of about half a meter and a thickness of a few centimeters: on the side facing the ground was Sofia's face (which had managed to look up just before the blunt object reduced her to her current state), confused and annoyed. Finally, her huge bosom occupied most of the coin face.

"How on earth did you manage to free yourself from that bottle???" the little pancake on the ground yelled, wriggling desperately but only managing to move her body a few inches.

"Nothing is impossible for your big sis," Carla said, lifting her sister's flattened body from the ground to admire it in all its flat splendor. "I don't understand why you complain every time I flatten you; you're definitely much cuter and more adorable in this state," she added, causing more complaints from her younger sister.

Carla turned her sister's body over: occupying most of the other side were Sofia's feet, still wearing her training socks (she had managed to take off her shoes just before the "incident"), with the rest of her legs compressed between her feet and her butt, wearing training shorts.

"HEY! Don't look from that side, you pervert!" yelled Sofia's ground-facing side, wriggling even more but to no avail.

"I was thinking of thanking you for the delightful afternoon you gave me in that bottle with a nice movie-night as sisters," said Carla, tossing her sister in the air and catching her again with the frying pan like a pancake, while heading to the living room. Sofia's protests were promptly ignored by her older sister.

"But these annoying noises might disturb us during the movie, so to kill two birds with one stone..." Carla said, tossing her sister's reduced body onto the couch and putting the frying pan on a table. She then began to fiddle with her sister's flat body, pulling and tightening the malleable object on the couch relentlessly. At the end of the work, Sofia's two huge breasts emerged from her coin-shaped body, almost challenging the rest of the girl's 2D body with their size. However, this change in body shape had required space on Sofia's front side, which now found her mouth covered by her huge cleavage.

"There we go," Carla said, wiping an imaginary drop of sweat from her forehead. "Finally, we found a use for those two melons of yours."

"BTTR THN BFLT BRD" ("Better than to be flat as a board...") Sofia grumbled in response, her mouth covered by the only parts of her body still in 3D. She immediately regretted commenting on Carla's breasts when she saw a glacial smile appear on the face of the person towering over her at that moment.

"I didn't understand what you said, but I think I got the gist, so..."

SMASH!

Carla's butt descended like a meteor onto the couch, crushing the pillow that Sofia had become. "Aaaaah, I've never sat on a more comfortable pillow than this, truly a cathartic experience," said the girl, moving her hips from side to side to crush her sister even more under her weight.

"And now... let's begin," proclaimed Carla, turning on the television. It was going to be a long night...

***************************************

...so long that late at night Carla had fallen asleep on the couch, using her sister's body as a pillow under her head. Sofia, however, forced to endure that treatment all evening, did not get any sleep at all.

"You'll see, big sis, as soon as I free myself from this..." Sofia thought, already anticipating revenge. She didn't have to wait long, as Carla, in a movement during sleep, freed her sister from under her head, and sent her bouncing onto the floor. The little pillow fell on the softer front side, bouncing on the floor before coming to a stop.

"Ouch! Oww!" said Sofia upon impact with the ground. "Well, now I have all the time I want to recover, and tomorrow morning..." the little pancake chuckled, oscillating slightly and beginning the slow process of reforming.

***************************************

"Yaaaaawn," Carla yawned, waking up peacefully on the living room couch; faint light filtered through the windows, indicating that the early hours of the morning had arrived.

"Good morning, princess," a sweet voice spoke to the newly awakened girl. "Would you like a nice cup of coffee now that you're awake?"

"Sure, thank you," Carla replied, still half asleep, rubbing her sleepy eyes. "Hey, wait a minute, where's that little..." Carla said, fumbling around for her homemade pillow she had used all evening before.

"SURPRISE!" Sofia yelled, grabbing her older sister's body and beginning to squeeze and compress it, eventually rolling her sister's body into a spherical shape, the size of a soccer ball.
"Not bad as a shape, I'd say, and I already have some uses in mind for this form of yours, but for now you're still too big for what I have in mind," said the newly appointed dough maker, compressing and squeezing the malleable object in her hand until it was the size of a baseball.

In Sofia's hand was a spherical object, on whose surface were randomly pieces of Carla's body, here a foot, there some fingers, with the predominant color given by the pajamas worn by the girl; standing out against the rest was an eye, with an expression far from satisfied.

Sofia, on the other hand, was already dressed in running clothes: sneakers, very short shorts barely covering her butt, and a sports bra with the daunting task of containing her considerable cleavage. "I thought, since you don't do much physical activity, of taking you for a run with me this morning," Sofia said, speaking to the ball-shaped girl she was twirling on her finger.

"But since you don't seem to be able to run in this form, and this dress has no pockets, I don't see any other way to take you with me than this," the athletic girl said, stuffing her sister between her huge breasts. The pressure inside was considerable, so much so that Carla had already taken on a more oval than spherical shape.

"There we go," Sofia said, squishing her two huge melons even more and putting even more pressure on her sister, which form was more resembling that of a coaster now. "Are you ready for some 10ish kilometers jog? It'll be a long morning.. between sisters, just as you wanted!" announced Sofia, opening the house's door.