"I found something interesting..." said John.
"Oh?" asked Sharon.
"There's a costume mermaid tail hanging by the bathroom. I think it might be your size."
"Lets take a look."
John led Sharon by the hand to the back of the room to where a tail hung on a large rack like a towel. It was orange and scaled.
"It reminds me of Madison's tail from 'Splash'" said Sharon. She pulled the tail off the rack and let held it on front of her, letting the tailfin fall to the ground. "And it does look like my size."
"Another hotel perk to go with the underwater theme." After a moment, John added "Want to try it on? I think you'd make a sexy mermaid."
Sharon smiled. "Lets find out."
She went back to the bed, pulled back the covers, laid out the tail, got in bed, and explained "Lets make it a surprise."
She pulled the covers over her and considered the tail. She had worn sandals so she had bare feet already. Sharon pulled her panties off, leaving only her bra and sundress. She slid her legs into the tail. Her feet fit somewhat awkwardly into the fins. A long zipper on the back made it much easier to get the tail up her legs than it would have been otherwise. The tail was a snug but comfortable fit and gave a feeling not unlike being wrapped in a warm blanket. All the while, John stood by the bed and watched with amusement at his wife's thrashing about under the covers. Finally, Sharon had her legs all the way into the tail which reached to her waist. She was a little surprised to find a conveniently placed slit on the front of the tail; clearly the designer had more than swimming in mind. Which was fine: so did Sharon.
Sharon flipped the top of the covers down to reveal her head and shoulders. "Time for the big reveal" she said. "Would you like to do the honors?"
John eagerly took the covers and pulled them down to reveal his wife's new tail which she tried to flick a little to imitate a mermaid.
"You look beautiful" he said.