A young man entered the pool, waiting to be changed. You and your fellow mermaid approached him, disguised as humans. You playfully cooed him into getting in the water, where you revealed your true form as a mermaid. Before he could react, you got on top of him, while your mermaid companion got behind his rear. You wrapped your tails around his legs, binding them together as they slow began to change. He moaned as his feet began to flatten and fan out, turning into two fins, which slowly became a orange tail fin. His legs began to turn scaly, and grow Gil’s as they began to bind together, slowly transforming into a orange tail. You pressed against him, his penis entering your mermaid vagina. You both let out a soft moan of pleasure before his penis began to recede into his tail, forming a slit. Suddenly, his hips cracked. Giving him sexy feminine proportions. With a satisfying gurgle, his stomach caved inward, being flat and toned, as the fat redistributed into his ass. As HER ass expanded, it became soft and round, giving her a sexy mermaid tail. By now, estrogen was filling what was left of her human form, as her frame shrunk to a feminine size. You felt out her arms and hands as they lost muscle and hair, becoming soft, smooth and dainty. You grinned as a orange shell bra materialized onto her chest. Your mermaid friend pressed her hands against the human’s sides, compressing her frame even more into an hourglass, while you rubbed her shoulders. Their shoulders slowly rounded and came closer together, while you began to kiss their neck. As it slowly softened, you watched their Adam’s apple disappear as their moans and gasps rose to a beautiful siren’s tone. You put your hands through their hair, as their brown hair slowly grew down their back. You kissed them passionately, as their lips slowly puffed into a sexy pout, being cute and kissable. Her jaw cracked, becoming softer and less square. Her nose shrunk to a cute petite size while her brown eyes got bigger along with her eyelashes. Her eyebrows thinned as one last change remained. You squeezed her body as she moaned loudly, her nipples now erect. With each gasp and breath she took, her chest began to rise, soon pushing against her bra until she had two cute C cup breasts. Her transformation was complete as you stared at your new mermaid companion.