Gabriel quickly threw on a bathrobe. Though he was sure it's Jeff he wanted to keep his mechanical legs hidden just in case. Running to the door felt surprisingly swift. Even though his new legs were somewhat more heavy and massive, they felt a lot more agile. Somehow they must have gotten a lot stronger to more than compensate for the added weight.
Opening the door revealed a smiling slim young man. "Thanks for letting me use your Chonivac", he said spinning his memory stick around his finger. Gabriel lead him to his streaming room dropping his robe, "Feel free to undress here". Jeff did so, showing off his not exactly impressive, but still cute body. From his erection Gabriel could tell Jeff was quite excited.
Coming back from the break Gabriel introduced Jeff, "Well this is Jeff here, he wants to try out something". Jeff nodded and handed Gabriel the memory stick who loaded it up. "Now if you could be so kind to apply it to me", Jeff asked politely to which Gabriel replied, "Only if you take me from behind". "Deal!", Jeff replied without hesitation.
Gabriel fired up the transformation and knelled down. Jeff, still fully human stepped behind him, pushing his erected member into his back port hole, causing both of them to moan. Eventually the changes kicked in. The first change was his member which grew in size and got a rubbery surface. Gabriel's sensors gave him a good "feel" of it. Although it seemed like it was fully made out of rubber it still was rather organic in its shape, clearly mimicking the shape of a human penis. Next in line was his ball-sack which also turned rubbery while his testicles became harder. He now really had balls of steel. Having gained an artificial reproductive system finally made him cum, shooting hot semen into Gabriel as they periodically thrust onto each other. The changes spread towards his lower body which became metallic and red. Unlike with Gabriel, whose lower body essentially became armoured, Jeff stayed organic being sculptured like muscles, like if his new parts were actually there to replace his old legs in an unobtrusive way. Though his feet gained a thin padding at their bottom, they clearly were meant to still wear shoes.
As Jeff's lower body became what appeared to be fully mechanic, the changes spread up. At first, fur started to grow on his remaining skin. It was red on most of it, except for his belly which was white. A white tipped furry tail grew from the end of his spine. At the same time his upper body and arms grew somewhat, making him appear more buff. Somehow the fur on his chest showed off his now muscular six pack. His right arm, however, changed differently. Just like his legs it became metallic like his legs. On top of his wrist a small bump appeared with a sort of lens towards the front, his own little Chronivac.
Then the changes spread up to his head. It too grew fur. His nose was pushed forward, along with his mouth to become more vulpine. His ears became more pointy and thin. On his eyes however a sort of visor appeared covering them completely. As it fully formed it revealed a holographic display with what looked like traditionally animated eyes showing him in the state of bliss also suggested by him clinging on to Gabriel as he shot his last shot.
Quickly they regained posture and Jeff faced Gabriel, with his new nose close to his face, "Wanna go _all_ the way?"