"Well", Jenny blushed as she nervously laughed, "would you have a problem if I wanted to... Be your cock?"
Jeff quickly turned red too, gaining an instant erection after the proposal. "Wow haha, I didn't expect such a level of intimacy but yes!" Jenny smiled noticing his excitement. "But one thing, it would be boring if you're just a boring penis"
"That's why I had a different idea in mind! You see, I'll merge with your crotch and work like a penis, keeping my arms, torso and head that will respectively replace the parts of your sexual organ"
"Oooh, okay sounds good to me!"
"Yay!" Jenny clapped, "let's set it to half a year, in any case we can change it at any time right?"
"Yes, it's more like a timer for the transformation but we can modify it as we want"
After the proposal and explanations of the Chronivac they began their kinky plan typing what they talked about on the computer. Jeff started getting completely undressed and sitting on a couch, waiting for his beloved girl which was slowly teasing him as she removed her clothes. They officially started when Jenny was completely naked, looking like she was about to sit on Jeff's legs just after she grabbed his cock and began to insert it inside her.
As Jenny completely shoved inside her boyfriend's penis inside of her vagina, her sex organ began to seal leaving a plain surface between her legs, consequently absorbing Jeff's cock, not like he's getting a better replacement. Then her legs merged with Jeff's just adding a little extra mass to them, resulting into her upper body stuck in his crotch.
Seconds later Jenny looked at her chest, noticing that her nipples were absorbed by her own breasts until they were a mere pair of smooth skin spheres attached to her chest, then said spheres started to gain wrinkles, Jenny smiled knowing what was happening now.
"Well, time to say goodbye to my titties" she giggled.
"I'll miss them too, but it's for a greater good" Jeff said deeply kissing Jenny again while grabbing her boobs turnrd into big testicles, which slowly moved down until reaching Jeff's crotch, taking the place of his new nuts as his previous one shrunk to give them space. Leaving Jenny's chest completely flat.
Her transformation was almost done, the only last thing that happened was that she shrunk s couple of inches but wasn't too different of her original size, being a massive 15 inches trunk merged between her boyfriend's legs, basically the size of half leg with a ballsack of the size of two soccer balls since Jenny's bust was really big.
Jeff and Jenny were still kissing, Jeff having to lower his head to reach Jenny's mouth which was functionally his urethra, he wanted to play a little more and used the whole palm of his hand to masturbate his girlfriend's torso, Jenny could feel the semen flowing through the testicles that now were part of her lower body, the fluid traveling to her throat until she couldn't retain it more. Jeff knew by his male experience what was about to happen, so the couple separated their lips for what as about to come, Jenny felt like vomiting, but in a somehow pleasurable way, expelling gallons of cum from her mouth until there was nothing left inside her, leaving large puddles of the liquid on the ground.
Jenny coughed, "um... Are you okay babe?" Jeff asked worried about his now humanoid female cock, she used her arms to clean her face.
"Ahem... Are you joking!? That was sooooo good!" She excitedly exclaimed, stretching her arms.
"Well, after all you were the one that came up with this" he giggled.
"Did you enjoy it too sweetheart?"
"Off course babe~" they passionately kissed again, mixing their tongues in the process.
The couple was excited for all the new things they could do in their new state, also Jeff's libido extremely increased since it was the only thing Jenny's body was assigned for, besides dealing with Jeff's pee.
"Hey stop! You're making a mess!" Jeff giggled trying to control his penis girlfriend, which was on purpose using her tongue to change the direction of the pee stream that came from her mouth, surprisingly it didn't taste bad, probably her taste was modified as a penis.
And with that a couple of days passed, still not a week yet and they were just covering the tip of the iceberg of their new life.