There is love, but war

All characters in this story are eighteen years of age or older.*

*The following story is inspired by Miss Evie Hyde's "Slut-Box Challenge" story. The following is written with permission from her to use her premise with my own characters and situation*

Billy checked his phone when he got the notification. It was a new email from something called the Slut-Box Challenge. He rolled his eyes and put his phone back into his pocket. It was likely some prank from Graham and his cohorts of assholes. Last month they signed him up for a box subscriptions for Male-for-Male Sensations. Those dicks.

His phone vibrated again, and he slid it out to check, this time pausing his game. It was the same notification from the Slut-Box Challenge. The subject was "Make Love, Not War," and the preview text was something about seducing your worst enemy. It sounded like some lame role-playing stuff. Billy sighed and put the phone back into his pocket, unpausing his game and continuing.

Without fail, every thirty seconds, his phone would vibrate with no new notification, just the email. Billy tried to ignore it, but it's incredibly difficult to kill orcs while something tickles your thigh every thirty seconds. He considered opening it, if for no other reason than to stop the notification, but what if it was a virus?

It was his lack of patience that damned him as he paused the game, unlocked his phone, and checked the email. He read the message multiple times, baffled at what it said:

Make Love, Not War - Seduce your worst enemy and let him cum in your tight pussy. If you don't do so in an hour, you'll be stuck in this body forever. If you complete this challenge, things will go back to the way they were.

What body? What pussy? An hour? Billy checked the time, it was 3:27. When was the email sent? 3:15. He had until 4:15 to let his worst enemy cum in his tight pussy? What the hell did that ...

Billy gasped as his pants tightened around his thighs. Then, slowly, they rolled up his ankle, his calves, his thighs, becoming shorts, short shorts, embarrassing shorts.