Katie clutched her belly as she felt an odd stretching that began to hurt as her womb stretched back out, slowly at first and then a sudden jerk, at a rate faster than it had shrunk. Katie felt what she thought as the growing Tiff inside her squirming and kicking furiously.
"Alright Tiff, I get that you're scared, ouch! That's my kidney! Ow! Ow! Ow! Calm down! I didn't want this for you either you know!" yelled Katie as she tried rubbing her expanding belly in a hope it would calm the growing Tiff. Given the speed with which this was happening now, Katie waddled as quickly as she could back to the bathroom, in preparation of giving birth. Thankfully the water from the bath was still there, even if it was rather lukewarm now, that was better than cold. As the last few weeks began to be approached, Katie felt her breasts begin to swell once again with the milk that had gotten her in so much trouble to begin with.
Just as Katie felt her bellybutton pop out like a meat thermometer, she lowered herself into the tub and felt a stabbing pain as she began to go into labor. Tiff however seemed to be eager to come out and rather quickly for a woman in labor, Katie felt herself push Tiff back out into the world and into the lukewarm water, with the afterbirth following not long thereafter.
Not nearly as exhausted as Katie thought she should feel, she reached down to grab Tiff up out of the water and get her breathing on her own again. It was then she found her stomach was shrinking once again, making her picking up Tiff a lot easier than it would have otherwise have been.
She brought Tiff up to the surface and gently patted her little back only to be brought face to face with something which frightened her immediately upon sight as the baby began to cry--a penis. This baby wasn't a girl like Tiff had been, this baby was a boy. What had she done... was this baby even her friend? Frantically, Katie brought the crying baby's face up close to her own, trying to discern if the baby features resembled those of her friend. Hoping that all had happened was some kind of sex change, nothing else. It wasn't until the baby opened its eyes and Katie saw Tiff's eyes and a small sliver of recognition in them--or at least that's what she thought it was, it might have just been a reaction to the umbilical cord curling up and falling out--that Katie felt reassured that this baby boy was Tiff... on some level at least.
"Oh Tiff... thank god it's you... I'm so sorry... so so sorry..." said Katie as she brought the baby in for a hug, smashing the baby against her swollen breasts that now began to ache on their own, at least until Katie felt a tugging on one, and looked down to find Tiff nursing at that breast.
"Oh yes... yes, of course you're hungry... and oh... oh... that feels good..." moaned Katie as her mind was transported back to the pleasure of having someone drink and drink from her breast.
As the boy who had been Tiff drank, his body began to stretch and grow, passing from infancy and into babyhood smoothly with baby fat and a full head of hair filling out upon his growing little form. Rather quickly he grew, passing into toddlerhood as his chubby body grew into perfect kewpie doll proportions and then began to stretch out of them and into childhood.
"Oh... Tiff... don't stop... please don't stop!" moaned Katie as she felt a rather ecstatic feeling at having her breast drained by so much so quickly. However the boy who had been Tiff came to the end of one breast as he heard his name and stopped and looked oddly at Katie and then at his pre-preadolescent self.
"I... I..."
"Tiff... please..." begged Katie.
"I don't want to be called Tiff anymore," stated the boy who'd been Tiff.
"Huh?" asked a clearly dazed Katie.
"I'm a boy Katie... not a girl. And boys don't have girl names." said the boy who'd been Tiff very definitively. It was odd, part of him felt betrayed by saying that, but at the same time it just felt right.
"Okay... what name do you want?" asked Katie, hoping that the boy who had been Tiff would hurry up and just finish his meal.
At once the boy who'd been Tiff thought... he knew what his old name meant, having had a passing interest in names before... well before the mansion had done this to him. Tiff had known that Tiffany was a medieval nickname for Theophania, a feminine version of the name Theophanus. Theophanus sounded wrong, stuffy and old... but Theo... Theo felt right to him. It was a way of keeping his old name, just making it a boy name at the same time.
"Theo. Call me Theo," said Theo confidently before feeling his stomach grumble.
"Theo... keep going Theo," whispered Katie, as Theo latched on to her other breast and began to drain it. At this point, preadolescene began to appear on Theo's features as his baby fat had mostly been stretched away at this point into a skinny frame which now no longer solely rested on Katie's body but streched over it and began to support him in the tub by himself. Hands and feet began cracking as they expanded, and Theo brought his one hand up to Katie's other breast to balance himself, causing Katie to moan as she took his growing hand and began to teach it how to cup her empty breast and massage its aching emptiness, causing her pleasure to increase.
As puberty was reached, Theo felt an odd itching sensation as hair appeared around his penis and his ballsac which itself was beginning to stretch as his balls dropped into them. As for his penis it was beginning to feel funny as it stretched and filled with blood, giving Theo his first erection as he began to find sucking from and playing with Katie's breasts to be erotic and her moans to be music to his ears he'd never known he'd long to hear before now.
"Oh, yes, Theo... yes... yes!" enthused Katie as she felt his little stiff member jut unintentionally against her vagina, adding to the pleasure of the moment.
Puberty continued to bless Theo as his frame stretched out, pushing his shoulders apart, his feet and hands further from his body, and muscle began to fill out his scrawny body. His balls grew plumper as they began to pump testosterone through Theo's body and his penis grew longer, and almost instinctively upon the urgings of Katie he inserted it into Katie's waiting vagina. Theo wasn't by any means a teenage heartthrob, but he was particularly handsome for his age with the lean build of a runner on top of it.
By the time that Theo had drained Katie's breast of the milk he'd been drinking and begun to engage Katie in actual kissing, Theo was once again returned to sixteen, only now as a boy instead of the girl he'd been, and one horny boy he was in the middle of satisfying his girlfriend. Girlfriend? Girlfriend. Memories that he'd had as Tiffany now began to rewrite themselves from a boy's perspective. He and Katie had still been friends growing up, but in recent months with the awkwardness of puberty having started to subside, they had begun to find themselves wanting to do things as more than friends. Tentative kisses had turned into experimental heavy petting, which had gone farther until now they were finding odd places to sneak off and have sex... hot wild crazy sex, and Theo was loving every minute of it. Feeling more confident and assured with each thrust he gave into Katie's pulsating vagina.
Katie herself was too lost in her own pleasures to notice her own memories rewriting to align themselves with the new reality of Theo having always been a boy and her friend turned boyfriend. Elsewhere in the mansion, where Tiff had lost her clothes, they reshaped and redesigned themselves into something an average boy would wear. And as both Katie and Theo reached climax and Theo unleashed his seed into Katie's womb, an energy wave erupted from the climax and reverberated across the earth, altering all the rest of reality to reflect that Tiff had always been Theo. His parents remembered having had two sons, not just one. His younger brother remembering how much Theo had tease him like only an older brother would growing up. Friends, acquaintences, and those influenced by them who'd known Tiff altering in slight and large ways as the effect that Tiff on the world shifted to what Theo had had on the world instead.
And unbeknownst to either Theo or Katie, his seed swam into her unprotected womb and found there an egg to fertilize, doing so and causing what the milk in the first place had promised, a pregnancy. It had taken a roundabout way of getting there, with many unforeseen sideeffects and reality alterations, but Katie was now pregnant, and things were only starting from here.