Alex watched his older brother as his small inny-belly-button inflated, popping out into a rubber air-nozzle; awestruck by the transformation taking hold before his eyes. He had yet to witness the Chronivac in action, and the bizarre and fantastical experience of watching another person become an inanimate object was hotter than he could have imagined. The front of his jeans bulged, and he had to adjust his growing arousal.
Zack let out a breathy moan, his 6-pack abs turning a soft cream-white as the rubber spread out from his new air-hose. As the cool rubber coated and replaced his skin, he could feel himself filling gradually with air, the rubber spreading as he was "blown up", his lithe belly rounding out until he had a pudgy inflatable gut.
"Unh~ Fuuck bro! This already feels sooooo good." Zack gave his new belly a firm slap, a rubbery-rippling smack filling the room. With both hands he kneaded the domed gut, feeling the rubber wrap around his love-handles and lower back, descending over the crest of his boy-ass. "Being a sex-toy is going to be so much better than a plushie!"
Alex blushed, still embarrassed that his brother was really going through with his kinky request. Though he couldn't help but lick his lips as the base of the rubber covered the under-hang of Zack's flat, toned boy-chest. "Yea bro, way better like this.."
There was a loud squeaking-pop of rubber-caught on rubber from Zack's crotch, drawing both of their attention between his hairy, human legs.
Zack's average human-dick was now half-rubber, the shaft flexing as it increased in girth, the rubber almost unfurling up the length as it was "blown up" similarly to his belly. The shaft squeaking as it ground over the bottom of his gut, gaining inch after inch of red-rubber cockflesh.
"Oooh god! Yeeees, more~" Zach gasped, his head snapping back in pleasure, tugging at his still human nipples as he humped his transforming cock into his big inflatable belly.
Alex couldn't take his attention away from that huge rubber fox-cock as it inflated from five inches... to six... to seven... bigger and harder. A thick knot forming at the base. This is what Alex wanted, it was beyond his wildest wet dream - and he wasn't about to restrain himself any longer. His bro was becoming an inflatable sex-toy, and Alex was going to...