John and Mary lay together on the side of the pool, holding each other after their lovemaking session in the pool. Having each taken half of the dolphin transformation vial, they remained mer-dolphins.
"I love the feel of our tails against each other" said Mary.
"It feels pretty good" John said and kissed Mary's neck. "But I have some ideas I'd like to try with you. There are other vials like the dolphin one right?" Another kiss.
"Yes, lots. They're in a case in that cabinet" she said pointing nearby on the pool deck. "What do you have in mind?"
"You got to surprise me now I get to surprise you."
John let go of Mary and pulled himself along the pool deck with his arms, having to drag his tail behind him. Fortunately, he could reach the cabinet and open it. Good thing Mary hadn't put them somewhere higher.
He pulled out the case and opened it, looking at his choices. As Mary had said, there were plenty of choices. He noticed two vials were missing: dolphin and human.