Just as Millie's mouth had open wide to begin singing, a single finger from Emma rested on her lips. Quickly her mouth shut again, an eyebrow raised as if to question why her girlfriend had stopped her from sharing such a wonderful gift. The answer came rather quickly. "If you're going to do this... we oughta be in some water, right?"
With a grin Emma rolled from the clutches of Millie's tail, landing on her feet and quickly picking up the mermaid in her arms. Carrying her girlfriend bridal-style, she leaned down, their lips meeting as walking became stumbling, blindly bumbling her way through the apartment with an excited fish lady writhing in her arms. It was lucky that the bathroom door was open - she was in no state to fiddle with a doorknob right now.
Millie had done an excellent job in pulling Emma's shirt off by the time they reached the bathtub, unceremoniously falling over as the mermaid-to-be kicked off her shoes. She worked at the faucet with her feet as Millie worked on the pants, jeans sliding off and getting tossed aside just as they had started to get wet from the spray of the showerhead. The cool water felt pleasant against her skin, though not half as pleasant as her girlfriend's hands ripping her bra off, nor her lips hungrily kissing along every inch of Emma's neck.
It was only once her panties had been ripped off, revealing a small tuft of brown hair that was already soaking wet, that Millie pulled away from her assault on her girlfriend's skin. Emma in turn lowered herself to grasp the mermaid's nipple between her teeth as the woman's moans turned to song. It was a strange sound, melodious and spoken in some language that she'd never even conceived of... and yet so beautiful, the most wonderful thing her ears had met with since the first time she heard a declaration of love from her partner.
Utterly hypnotized by the song's grace - not to mention rather busy with suckling at one of Millie's breasts - Emma could hardly resist as that rainbow-colored tail wrapped around her legs, pulling them tightly together. Despite the constriction, lust drove her to grind her hips against the place where Millie's tail met her upper body, and with a gasp of surprise she was rewarded with the scales parting to reveal the soft womanhood she had given so much attention to in the past. Fires unequenchable by the cold liquid pouring down on them burned between her legs as she pulled herself as tight as possible against the mermaid.
The heat spread rapidly down her body, and Emma instantly knew that she was about to receive the same miracle that her lover had experienced. The skin of her legs had already meshed together, leaing no gaps between limbs as the flesh was almost magnetically drawn together. What she had always felt as two separate parts of her body now unified at a rapid pace, muscles now merging together, followed by bones crashing into each other and spreading out into flexible cartilidge. Her feet joined at the heels, spread out ot the sides and quickly flattening out, sacrificing thickness for a much greater width.
Definition vanished from her knees and ankles, even from her hips. In its place was only a smooth mass, covered in the same skin as before, yet left in a shape near identical to the beautiful lower body of her partner. Emma's new tail swished and writhed as it grew out, lengthening itself to easily six feet before stopping. The heat that she had felt raging within her lower body quickly shot up her spine, and from there, spread out over her whole body, drawing a scream of ecstacy from the woman as she basked in the glorious sensation of her whole form being shaped like clay.
Her hair, always kept a little on the short side, rapidly grew out, its color becoming a velvet-red sheen as the thick mane cascaded all around her shoulders. Her chest was tugged, yanked outward, previously modest endowments becoming firm orbs of considerable size that hung perkily from the front of her body. She cried out in joy as the whole of her skin was robbed of any blemish or imperfection, becoming smooth as silk, the tone darkening ever so slightly. By the time Millie leaned up to kiss her once more, her lips had become full and soft, a ruby red shade that perfectly matched her flowing locks of hair.
Hands entwined in between each other's tails, fighting recklessly to reach inside grinding slits. Any councious or rational thought vacated Emma's mind at the touch of her partner; she was consumed utterly with carnal desires, desperate only for one thing, that thing growing closer with every moment they spent writhing around together. Finally, her body could hold back the floodgates no more; with a screaming moan of excitement that seemed to blend into a beautiful song, she felt a sweet release, her whole body thrashing wildly as Millie's did the same.
They rode the high for what seemed like hours, only relaxing when all the fight had been drained out of them. With an exhausted contentment Emma sighed, her tail flicking up to shut off the water as she crawled up to lay against Millie, her partner's own body already laying against the back of the tub as she panted heavily. There was a long, long period of silence as they simply lay in each other's arms, grinning and enjoying the afterglow of their experience, only interrupted when Millie finally regained the wherewithall to speak up.
"You... don't have scales." She pointed it out, and Emma looked down, curling her long, skin-covered tail. The other woman's assessment was correct - she was a mermaid with a tail as smooth as butter, covered in the same skin as the rest of her gorgeous form. The way Millie had said it, however, carried no malice or disappointment. "God... how can you always be so hot... without even trying..."
Emma shrugged as she laughed through several ragged breaths. "I have a talent." She hadn't quite expected to take on this kind of form, but that was an irrelevant fact - she'd never felt anything so wonderful as her tail curling around Millie's, their bodies hopelessly intertwined.
"Thank you for this," she whispered as she laid her head against Millie's shoulder. Their bout of lovemaking had drained her physically, and very soon Millie found herself drifting off to sleep - before she passed out, her last thought was only of how lucky she was to have such an incredible girlfriend.