Mermaid folklore

There are numerous stories about how mermaids walk on land. One story from the Orkney Islands tells how mermaids disguise themselves as seals when in the sea but that they take off their seal skins on land. In this story, The Mermaid Wife, a fisherman discovers a group of mermaids on a beach. All the mermaids grab their seal skins and dive into the water except for one unlucky mermaid. The fisherman grabs her seal skin and forces her to stay on land and marry him! He hides the skin, but many years later, one of their children finds it and brings it to her. The mermaid, who'd never stopped longing for the sea, immediately races back and puts the skin on, leaving her family behind forever.

A French fairy tale tells the story of Melusine, a freshwater mermaid whose fish tail reappears every Saturday. Melusine keeps this secret from her husband for years, but his curiosity gets the better of him and he spies on her in the bath. She flies into a rage and leaves him and their children.

Notice a theme here? No matter how long or why a mermaid walks on land, the urge to return to the sea remains strong in her.

The most famous story of how a mermaid gets the ability to walk on land is from The Little Mermaid (although Disney changed it significantly). In this story, the mermaid pays for her legs with her beautiful voice. Even so, every time she walks it feels like walking on knives. Worse, she can't stay human indefinitely. If the man she loves falls in love with someone else, she'll die and become sea foam the morning after he gets married. When The Little Mermaid gets the chance to return to the sea by killing him, however, she refuses. Because of this, heaven takes pity on her and makes her a daughter of the air where she can do good deeds and earn a soul.

In my version, the mermaid learns from an old woman that she can appear to walk on land. She can only do this for a few minutes and as long as she's near water. However, when she falls in love with a man, she asks the old woman to help her put off her tail for a chance to spend more time with him. The old woman warns her that the transformation is dangerous, uncertain, and only lasts for the rainy season. If my mermaid consummates her love with him, she can keep her legs.