Jeremy got into the game, but he mostly concentrated on the girls in their bathing suits, especially the cute blonde who was about his age with perky bumps of tits in her suit and a beautiful butt.
Hoping to cop a feel of her behind, he swam over and pretended to hit the ball, but then "post his balance" and his hands went out. The girl tried to save him, swimming over and getting her ass grabbed. She squealed in surprise.
"FOUL!" the referee cried. "PENALTY - SWITCH!"
Jeremy was about to ask what that meant when his body felt strange. He looked at the girl - and it wasn't a girl, it was HIM!
"AAAH!" he yelled - but noticed his voice was higher. He put a hand to himself, and discovered small breasts and an absent penis! "What happened?!"
"Calm down," the copy of Jeremy said. "It's the penalty for a foul - getting our forms switched. When the game's over, the referee will restore us. It happens all the time."
"Uh," Jeremy-girl said, not quite believing what just happened, despite the evidence. "Are you sure?"
"Happens to me all the time," the girl-Jeremy said. "You'll see -"
:BOINK!: the ball bounced off their heads.
"SLOW PLAY!" the referee called. "TEN MINUTE PENALTY! OUT OF THE POOL!"
Grumbling Jeremy-girl and girl-Jeremy swam to the pool's edge and sat on the deck chairs. Jeremy couldn't help playing with her boobs through the pink swimsuit.
The copy of Jeremy laughed. "Some things never change. You horndog."
"Me?" Jeremy-girl accused, pointing to his duplicate's hand inside the swim trunks. "That's my dick you have your hand on!"
"I know. I like dicks."
Jeremy-girl flushed, her face getting red and her nipples hardening.
"It was hard for me at first, too. My name's Alex."
"Jeremy."
"Just here for vacation?"
"That's right."
"I've been here twenty years."
That got Jeremy's attention. "Alex continued, "It was a water volleyball game just like this one, although I was a college student with a thing for young boys. When I tried to feel one up - just like you tried to do to me - I got fouled and switched with the boy. The kid decided he liked being a college student better than a kid, so he left with my body. I tried to get other bodies, but not that many grownups play water volleyball. After a while I decided to live with it. I switch around with kids at the game, sometimes on or the other decides they like the new body better and leaves. Sometimes accidents happen and it takes a wek or so to switch again. Personally, I prefer being a girl. Girls can get cock real easy."
Jeremy was geting very uncomfortable. Alex grinned at her.
"Hey - want to have some fun?"
"Like what?" Jeremy asked.
"If you get laid like that, you'll know how to make a girl feel good. And when we switch back, you can screw that body yourself."
Jeremy considered that. Getting expert knowledge of how to make a girl feel good. And getting laid twice!
"Deal," Jeremy said.
Alex smiled and took Jeremy's hand, and the two 13-year-olds went to the locker rooms and showers.
In the showers, their bathing suits came off and Jeremy learned how GOOD it felt for two naked bodies to hold each other and touch and kiss. Alex's expert hands - with over twenty years of experience - made Jeremy's borrowed 13-year-old body quiver like a plucked harp string.
Pushed against a wall, Jeremy found Alex's tongue burrowing into her pussy, making her whimper and grind her hips. The climax was unlike the one she had in her male form - instead of a quick burst, it swept over her in waves, her body jerking and spasming. And she was still jerking and spasming when the HUNGER for having SOMETHING inside her began to burn. Fortunately, Alex pulled one of Jeremy's legs up and slid into her tight teen pussy.
The fucking seemed to last forever, but neither one cared. They just didn't want it to stop. But eventually, they groaned and cried and climaxed, Alex's borrowed cock sperming inside Jeremy's borrowed pussy.
The twosome held each other for a minute, then smiled and pulled apart. Jeremy was already planning on what to do to Alex when they were in their own bodies again.
And when they went outside - the volleyball pool was empty.
"Damn!" Alex said. "We must have missed the game!"
"Fuck the game!" Jeremy demanded. "How do we change back?!"
"Wait until next week, when the referee comes back."
"NEXT WEEK!? I'm only here for the day!"
"Then you'll have to come back next week."
Jeremy was beginning to panic. "How can I wait a whole week? I came here with Mike and Zach - how do I explain this to them?!"
"Don't worry," Alex said, putting an arm around her shoulders. "This isn't the first time this has happened. I have a plan."