You think to yourself, what a wonderful girl you have here. You carefully position the chair with the bowl of water under her raised feet and lower them in until completely covered. Lydia giggles and flips her feet out causing the water to splash over you. You ignore your sopping pants as you watch her feet transform.
The spandex runs down the insides of her feet hooking over her big toes. Slowly they are pulled together into a pointed position. The gap between her feet disappears as the short span of fabric moves to the end of her feet. Now one appendage her feet are bound together at the big toe forming the tip of her long body. Lydia spread and flexed her other toes in an attempt to force her feet apart but it seemed no longer had that option.
Lydia's heels shrank away now and the rest of her feet seemed to widen. She made a sound of distress as she felt her toes lengthening and the skin and muscle of her feet being pressed flat by magic. The skin of her feet started to turn a bluish colour as her feet extended out and down further than the tip of the spandex. Each side became flat and formed an oval fin shape that was about a hand length wide and twice as long. The bones of her toes formed nubby spines that ran the length of the fins to keep them stiff in the water. The blueish colour solidified into a glossy, soft-rubber material much like swimming flippers. Now Lydia looked like a complete mermaid.
"I ... still don't feel complete," Lydia gasped looking up at you. "Dump the rest of the water all over my body."
You hesitated for only a moment thinking about damp mattresses before complying. You dribble water slowly up her body starting from the narrow end and moving up. You linger at her mid-section a little thinking about your eager cock which had gone into overdrive watching her feet change. Then you up ended the bowl's contents on her head soaking her hair. Returning quickly to feet you use the washcloth to spread the slopping water more evenly.
The soaked in water changed her legs. There was no longer the impression of two legs held extremely tightly under a tight spandex skirt. The bones and muscle structure reformed to be a tight flexible spandex covered body. Her thighs and hips reformed a little to make bending over backward at the hips possible. You could also see the spandex tuck in tight at her crotch. A fold appeared and sank deep into her body right where you expect to find a girl's private parts, but the tight muscles around the fold suggested that unless she relaxed her body, nothing, not even water was getting in further.
You look at Lydia in wonder. Her head had changed a little. The slight red of her brown hair had now become a shocking turn of colour. Her long red locks fell about her head in a striking manner that accentuated her slightly narrowed features. Her nose seemed smaller and pointier. Her cheek-bones pushed her face forward into a slight snout and her chin became small and pointy. The whole effect gave the impression that she was built for speed underwater. You find it sexy if a bit unnerving. But Lydia was smiling at you and her eyes seemed wet and wide with wonder.
"How do I look?" she asked.
"Beautiful," you say leaning in to kiss her.
She responds and soon you are laying next to her. You cup her larger breasts and stroke the soft slippery spandex skin. Lydia in turn runs her hands down you body and holds you tight. Her tail now animated and more flexible than ever twists and wraps around one of your legs. You in turn hook your other leg as high over her hip as you can.
Entwined like this you kiss and pet each other while the storm rages outside. Your fantasy has finally come to life and your mind races to take it all in. As much as you want to enjoy the moment you start thinking about your options.