Herself masturbating.

Vivia felt as though she'd been asleep, without any memory of how she fell there. Her eyes slid open to a sideways view as she lay face-down on a bed of warm stone. She remembered it being light out, so the bright sky told her she wasn't asleep long. As her eyes focused, she saw a puzzling sight.

Kneeling beside her on the rock was herself, in the throes of masturbation. Her own tan legs splayed as she furiously worked her fingers inside her pussy, with her other hand twisting one nipple up on her bare breasts. Her face was lost in a heated expression of ecstasy, eyes crossed and fluttering as her tongue hung out to drip drool on her own chest.

She recognized her voice, panting and moaning. As Vivia struggled to rise, she quickly found her body didn't work as she'd expected, and she immediately fell back down with an unfamiliar cry. A curtain of fair hair fell around her vision, and she came to the realization that she was no longer herself.

Trying to sit up with a tail was quite difficult, so she resigned to pushing herself up on her hands. Dragging herself to face her real self... old self... whoever possessed her body, Vivia adopted a fierce scowl. The ex-mermaid seemed too enthralled in the act of pleasuring herself to notice, her panting speeding up with her hands before crying out in an apparent orgasm and slumping down on the stone.

“Hey!” Vivia croaked, not used to the voice. She worked her mouth into a gulp, and found she could still taste herself. “You!” she cried with more confidence.

Her actual body lay back on her heels, simply heaving heavy breaths for a long moment. Vivia reached out a hand to grab at her knee, and the touch spurred the ex-mermaid into a moan.

“Legs...” came her voice. It disturbed Vivia, but she wasn't about to be put-off for long.

“Give me back my body!” she demanded, finding her new voice quite smooth in her throat. The demand was met with a long sigh. “Hey! I mean it!”

Slowly, the ex-mermaid drew herself back up on her knees, and looked to Vivia—in her former, mermaid form—with a sultry, satisfied expression. “You have a wonderful body,” she said then. The tone was eerie coming from Vivia's own mouth.

Vivia gaped at her naked, lust-laden self, face flushed with anger and embarrassment. “I want it back,” she said, a mixture of plea and demand. “I don't want to be... this...”

Her expression turned contemplative, yet still remained awfully blithe. The ex-mermaid rose to stand, high above Vivia's mermaid form, and her hands returned to fondling herself. “But legs are so much fun...” she moaned. “Especially the parts between...” She closed her eyes and tipped her head back with a sigh.

Vivia felt ****. Would she be stuck as a mermaid? “Please,” she said. “Give it back...”

Her own face turned back down to fix her with a half-lidded stare. “I suppose this lack of magic isn't fun...” As she spoke she continued to slowly masturbate, letting out a soft gasp. “If you'd help me indulge in this body's uses... I could help you take it back...”

Vivia looked up at herself through the mermaid's eyes, her frown turning skeptical. “How would I help, exactly?”

The ex-mermaid looked down at her legs longingly. “There's so much to experience...”