"As I said, I'll have some fun with you Jeffy~"
Hilda typed on the Chronivac after she listened to her brother's instructions on how to use it, she wrote to give herself a 8 inches dildo, Jeff's mouth watered again. Previously Hilda couldn't insert toys or dicks bigger than 6 inches due her small and stretchy vagina, but now with Jeff's long throat morphing into her vaginal track she could probably bear any size.
Hilda removed her shirt and bra as they were their only clothes left because she was already naked from her waist down, she examined her body in front of the mirror for some seconds.
She looked beautiful as always, showing off her firm D cup breasts and busty but wonderful pear shaped body, the only peculiar thing was her crotch, the transformation turned her blonde heart-shaped trimmed pubic hairs to black, matching Jeff's previous hair color after his hair fell off with the transformation. His face wasn't noticeable with Hilda standing, as his head was slightly shoved inside Hilda's crotch hole no longer called a vagina because her bother was the actual vagina. His head couldn't get out accidentally as the rest of his body merged with Hilda's reproductive system.
The big sister laid on the bed with the dildo in her hand spreading her legs. She gave a little look to Jeff, in that way he was immediately noticeable rather than standing, it was his entire face between her legs, with her pubic hair on top. "I must say that as my pussy you look even prettier little bro~"
"I... U-umm, thanks sis" Jeff said blushing, he wasn't against being his sister's vagina, but he wasn't excited as her.
"Say aaaaah Jen, now that your mouth is way bigger than my previous pussy." Jen followed her sister's orders, opening her watering mouth in front of the penis, the sensation for Hilda was like spreading her vagina in a way she couldn't imagine before.
Just inserting the the tip of the sex toy Hilda let out a moan, Jeff was feeling the pleasure too but Hilda felt it more intense, feeling her brother's and her own pleasure at the same time, she knew she was about to completely love it and they were just starting.
Eventually inserting almost the whole thing Hilda excitedly felt for the first time the sensation of having her vagina filled, as before it wasn't deep enough to fit many sizes, but now Jeff could handle everything. Meanwhile her little brother was feeling his throat being occupied by the dildo, it didn't give him a sensation of wanting to vomit as he didn't had a throat but a vaginal track, he was just doing his job. Then Hilda rubbed Jeff's noise as it acted like her clit, the sensation for him wasn't like wanting to sneeze but duplicating the pleasure he and Hilda felt, his sister began to moan even harder.
Hilda got even more hot with time in her pleasuring session with her brother, until she wanted to go even further, she removed the dildo and introduced three of her fingers simulating her g spot, her hand could easily fit as Jeff's original mouth was really big and stretchy, now even more as a vagina, Hilda knew that so why not shoving her entire fist? She did that immediately.
Hilda was drowning in wonderful sensations giving small punches to her insides as Jeff swallowed her whole sister's hand, the space inside him was so him that they didn't know what were the limits, but seconds later Hilda reached the orgasm, starting to squirt. Jeff puked a stream of his sister's fluids, tons and tons of the watery liquid coming from his second small hole being Hilda's urethra until there was nothing else more yo expell, leaving a salty taste in his mouth.
Hilda was laying on the bed tired after masturbating, Jeff kept squirting drops of her cum until stopped. "Oh... that was really great big sis!"
"I'm happy to hear that from you! I know this week is going to be so good~ hehe" Hilda giggled.
Some days passed before the week finished, in that time Hilda's got her period, the Chronivac did that she couldn't feel pain from it, not even Jeff more than feeling how "his" womb and sexual organs twisted and changed, also the taste of blood in his mouth wasn't bad, maybe the Chronivac automatically modified his taste to handle every fluid coming from Hilda.
She tried to use tampons but as her vagina was way bigger from the inside Jeff accidentally ended up swallowing a couple ones, so she finally went with using pads, Jeff didn't have any problem with it even that they covered his entire face, he also didn't mind wearing panties, his brain fusing with Hilda's sexual organ, nerves connected with him and her hormones fluctuating through him made Jeff think it was a normal part of his job as a human vagina.
For the clothing Jeff didn't have any problem for example the panties and pants like said before, but there was some days where Hilda wanted to toy even more with her brother, inserting vibrators or vaginal balls, sometimes both! Going outside and feeling the pleasure of them as she walked, Jeff enjoyed it too.
As for their social life, the transformation also made a reality alteration as Jeff selected yes on a checkbox about it before his vagina transformation. Everyone thought it was normal for Hilda to have her brother as her sex in her crotch, when Jeff needed to talk with his friends Hilda just opened her panties to reveal him, she used skirts very often to make it easier to show him, but sometimes decided to hear pants if Jeff didn't want to talk in public or if Hilda also didn't want it. No one questioned that as only Jeff and Hilda knew the truth.
The week passed, there was some hours left to make Jeff return to normal.
"So, that's it? In some hours you'll return to normal?" Hilda was not so excited asking that, looking at her naked crotch talking to Jeff.
"Yes, that was the time I set before to have some fun in this state"
"Aw... But would you like to... stay like this?"
"What do you mean?"
"Like, being my human pussy... Forever..." Hilda smiled.
She thought the many possibilities, her enhanced sexual life, getting rid of the pain of her period, getting closer to her little brother, will it be easier to give birth like this? She saw it as a possibility.
Jeff would probably say no, he surely enjoyed the usual but exciting experience of being his older sister's human pussy, but he shouldn't want to live like that the rest of his life, but as his brain was unwillingly affected by Hilda's body his opinion was different, he ended up agreeing with her.
"Yay!" Hilda jumped in excitement, she hurried to the Chronivac to type the new settings, she paused the duration of the transformation and erased the time to set it permanently, only she could change it and no one else even if they had access to the computer. Nothing happened more than Hilda and Jeff feeling a tingle, the change was done.
"Now we'll be together together little bro~ this whole human body part thing is addictive."
As Jeff thought before, Hilda ended up being way more excited than him with the transformation, he wondered what she could do, now he was entirely at her mercy as his older sister and new permanent owner.