Miley began to sing the same song she used for Julie. Derrick immediately leaned back and grunted. His sister resisted turning around because she didn’t want to risk seeing him naked. Thus, she missed it when the boy’s body began to change in unexpected ways.
Rapidly, he lost a bit of height and his developing musculature, becoming small and delicate like Kimmy. Hair sprouted long and luxurious, running down to his lower back while his face softened and became cute and feminine. Then, his figure shifted into an hourglass with a narrow waist and wider hips. Slowly, his nipples grew and poked out as the flesh behind them swelled into perky B-cup breasts. Meanwhile, his young manhood slipped inside to be replaced by an equally young womanhood. This new feature could only be seen for a second before scales spread over it, hiding it from casual view. Human legs merged and flowed out into a lovely tail covered in gleaming scales. Finally, a seashell bra materialized over the new mermaid’s breasts, marking the end of her transformation.
At this point, Miley let out a breath as she watched Derrick’s large blue eyes flutter open and go immediately to her chest.
“W-What happened to me!?” She squeaked.
Hearing the mermaid’s unfamiliar voice, Julie whirled around and gaped at the sight of her brother, now her sister. “The heck!?”
“What’s wrong?” Miley asked, frowning at their reaction.
“You turned me into a girl!” Derrick shrieked. Her eyes drifted to her tail. “You made me pink!”
“Actually, I’d call that magenta,” Miley noted. “And of course I made you a girl. What else could I have done?”
“You could’ve just made him a merman,” Julie suggested, trying to remain calm herself. A different part of her studied her sister in fascination, noting how much she now resembled herself. I’ll never look at the brat the same way again, she thought.
“A merman?” Kimmy tilted her head. “What’s that?”
Julie frowned. “Like, a male mermaid?”
Miley and Kimmy both burst out laughing. “A male mermaid!? Now that’s something I’d like to see!”
The Anderson siblings gawked in silence for a while. Julie eventually found her tongue. “You mean, there’s only female mermaids?”
“Yes. I couldn’t make a male mermaid even if I tried. It’s impossible. That’s why all mermaids find human males so fascinating. We have no such counterpart for ourselves.” Then, she gazed at Derrick with wide eyes. “So, you didn’t know.”
Derrick tried to cross her arms but found the position awkward with her new assets. So, she dropped them again and blushed. “No. I didn’t.”
“Oops,” Kimmy spoke for all of them.
“I…I can turn you back,” Miley offered.
Derrick started to respond but stopped. “Back? You mean, this is reversible?”
“Yes, of course,” Miley nodded quickly. “I mean, I returned your sister safe and sound, didn’t I?”
“True,” Derrick conceded before sighing. “Well, if that’s the case, I may as well see what this is like. I have been a bit curious.” Her blue eyes darted to her sister. “About the swimming and breathing underwater part, not the girl part.”
Julie smirked, her earlier trepidation now replaced with intrigue. “Okay, if you’re fine with this. I just wish I had a camera.”
Now more relaxed, Derrick smirked back and hefted her shell-covered breasts, giving them a good squeeze. “Yeah, well, you’ll just have to get a good eye-full instead.” Her smile faded to surprise. “Oh, wow!”
“You like that?” Miley giggled.
Derrick’s face glowed crimson. “I-I…uh, it’s certainly different.”
“Well, if you’re done groping yourself,” Miley laughed. “We’d better get going. Come on.” With a flash of tail, she vanished. Three more colorful tails briefly caught the sun before disappearing after.
Then, the beach was empty, again, except for a lone, forgotten copper-hued mermaid tail lying in the sand.