Jenn tried to keep her legs wrapped around Oliver, but they were steadily feeling weaker. With the last of her strength, as Oliver gave a particularly deep thrust she squeezed her legs to drive him even deeper. Oliver climaxed. She lost all feeling in her legs, but started orgasming and kept orgasming. With Oliver was pumped out, she drifted free of him and he collapsed into the shallow water, utterly spent. Jenn's body continued to spasm uncontrollably as waves of pleasure swept over her, like nothing she'd ever experienced before. The gentle surf deposited her half onto the sand, her legs still in the water. They flailed about and contorted as they slowly merged, like a zipper moving downward from jenn's crotch. She didn't know when the pleasure would end, or if she wanted it to. The sensations were so powerful she let out an incredible scream, albeit of pleasure not pain, then briefly blacked out.
---
"Jenn, Jenn, wake up!"
Jenn blinked the world back into focus. Kelly and Oliver were on their hands and knees on opposite sides of her, clearly concerned.
"What happened?" Jenn felt hungover. She had a vague recollection of having sex with Oliver then...why did her legs feel so strange?
"Whichever one of you is kneeling ON me please get off" she asked.
Oliver and Kelly looked at each other in confusion.
"Jenn, there's something you need to see..." said Oliver. He helped her up into a sitting position.
Jenn stared in disbelief. Where her legs had been was now a sky blue fish tail. After a moment of shock she closed her eyes and tried to imagine wigging her toes. She opened her eyes again and saw her tail fin flipping gently up and down.
"I'm a mermaid!" she exclaimed. "This is amazing!"
---
Jenn desperately wanted to try her new tail out, but realized after everything that had happened she was simply too physically exhausted. Oliver carried her up the beach to their little camp while Kelly gathered up some fruit. Kelly had indeed suggested to Oliver that he pleasure Jenn. They were trapped out a deserted island and horny, and Kelly didn't want jealousy. Oliver hadn't required much persuasion, of course.
They talked about Jenn's transformation, but the fact that neither Kelly nor Oliver had transformed at all. Jenn suggested it was probably due to her long swim across the lagoon. Something about the water. Even though it hadn't happened yet change was surely inevitable for Kelly and Oliver too. Kelly was far from thrilled at the possibility due to her difficulty swimming; she vowed to stay on dry land and void tranforming.
Oliver wondered about the role of the juicy fruit that all three of them enjoyed so much. Jenn hypothesized the fruit was just an aphrodisiac - it didn't cause the change but simply helped ensure it would happen. All three of them looked forward to partaking in the fruit again.