Tiffany felt the lump continue to press against her skin. Katie too felt something pressing against her stomach. Katie leaned back and gasped when she saw that her friend was growing a penis. The nub was getting longer and thicker with every thrust Katie made.
"Ooooohhh!" Tiffany screamed as her penis shot forward. It was instantly erect, and a respectable ten inches long. Katie wasted no time in yanked her balls from Tiffany's still intact snatch, and sucking her friend's new cock. Tiffany threw her head back, her eyes rolling up into her head. The feeling was... incredible to say the least.
There was a loud "pop" as Katie removed her mouth from Tiffany's rock hard cock. Katie spread her legs, and lifted her balls to present her dripping cunt to Tiffany.
"I need you Tiff." she said softly. Tiffany looked at her friend's wet slit, and didn't hesitate to put her new appendage to the test. It took a few tries, as she wasn't used to it, but eventually her cock found its mark. Both girls moaned as Tiffany pushed inside. They were both so wet her cock slipped inside with little resistance. And then Tiffany started to pull back, slowly.
As she did, Tiffany felt her cock growing. Its girth increased, and Katie's vagina was stretched to accommodate it. Katie nearly blacked out when Tiffany pushed herself back inside. And as Tiffany kept pumping in and out, Katie felt something pressing against the skin above her own balls. A penis of her own was quickly growing as her arousal built.
"It's...I'm going to..." Tiffany didn't finish the sentence. She came, copious amounts of white spunk being swallowed up by Katie's hungry snatch. Her first male load exited her body with such force and urgency Tiffany could hardly keep from blacking out herself. Her girl cum mixed with her boy cum, heightening the feeling.
Tiffany was too spent to notice that after she came, Katie's cock shot forth and started expelling cum of its own. There wasn't as much, but it still covered Katie's front. The sticky white substance was everywhere. And Katie could hardly do anything but moan and stroke her new shaft.
Both girls passed out as they finished cumming. But as they laid there in their own cum, they failed to notice that they'd knocked several vials off the nearby table. And their bodies quickly absorbed the corruptive and transformative liquids.