Kendra and her boyfriend, Shawn, had found a magic soap. All they had to do was rub it on each other's body and think about what they wanted to transform.
As they made out in the shower, Kendra ran her hands across Shawn's mid-section, eliminating the fat and toning his body. When her hand found his cock she dragged her fingers along his shaft, feeling it jump to attention and grow even longer beneath her touch.
Shawn slid his hands around each of Kendra's breasts. They ballooned out beneath his touch, growing fuller and plumper as he circled her smooth skin. When he was done her tits were massive, heavy things to match Shawn's new cock.
They could afford to mess with each other because the changes were only temporary. After the soap was rinsed off they would slowly return to normal. But until then, they could enjoy the transformations they'd made to each other.
Four friends accidentally discover that a mysterious remote control can transform them into duplicates of people on television in Remote Chance, available on Smashwords or Amazon or wherever ebooks are sold. Preview here.