The next morning, Oliver went spearfishing down the beach, which left Jenn and Kelly at the camp.
"You're a really sexy mermaid, you know that?" said Kelly, passing one of the juicy fruits to Jenn. They cracked their fruits open and began to enjoy the sweet fruit. Juice was soon running down both their chests. Jenn's movement was limited by her mermaid tail, but Kelly took the lead, straddling the new appendage. Soon they were licking juice off each other's chests before two slowly, tentatively met for a kiss.
"This is a first for me" panted Kelly.
"I would be pretty surprised if you'd been with a mermaid before" teased Jenn. Then, after a pause, she added: "Me too."
Hands and tongues explored. Fingers probed. Nipples were played with. Both women grew wet with anticipation. Kelly went first, finally leaving Jenn's breast behind as she kissed down her friend's stomach. All the while Kelly slowly slid down Jenn's tail, enjoying the feeling of it against her womanhood. Finally Kelly's tongue slid into Jenn's vagina, which was still in the same place despite the tail. She licked and probed and pleasured until she felt Jenn shudder. The orgasm squirted fluid down Kelly's throat and she broke off her oral pleasuring, flopping back onto the sand and gagging a little.
A moment later Kelly felt a strange tingle all over her body. She tried to stand up, but couldn't due to her wobbly legs. Then next thing Kelly knew Jenn's face was in her crotch, her mermaid tongue longer than a human's and being put to good use. Kelly felt a strange sense of foreboding, but it was overwhelmed by the pleasure from Jenn eagerly eating her out. Kelly felt the urge to wrap her legs around Jenn's torso. When she did so, Kelly realized something wasn't right. Her legs wrapped around Jenn too well and the tips of her feet could still touch the ground.
Jenn drove Kelly into a series of orgasms. With each orgasm, Kelly's legs gripped Jenn tighter, until the mermaid had to stop.
"Kelly" she gasped "I'm having trouble breathing."
Kelly relaxed. Her legs loosed and uncoiled from around Jenn. The mermaid gasped. "Your legs!"
In the post-orgasmic bliss, Kelly was slow to to realize what was going on. Then she saw her legs - or more accurately the two long purple tentacles her legs had become. Kelly screamed.
She wasn't turning into a fish tail mermaid like Jenn; she was turning into a cecaelia.