Muse A hates the beach. The only reason they’re here is because the bought this stupid beach house for the summer, to propose to their boyfriend/girlfriend/partner, that dumped them three weeks ago. The trip was non-refundable, and Muse A would hate to see all that money go to waste too.
While walking on the beach they spot what looks like a dead animal, but is really just a pelt, laying on the beach. Thinking that it’s interesting, and a much better souvenir than some stupid seashells, they decide to take it home with them.
The next day, Muse A spots someone, Muse B, looking around the beach for something they seem to have lost. They can’t seem to remember what they lost though. Muse B takes an immediate liking to Muse A and asks if they could spend time together. Confused, but flattered at the attention from a beautiful stranger right after being dumped, Muse A agrees and takes Muse B home.
Muse B is an amazing person, but Muse A can tell that something is off. They’re always cold, they eat way too much fish, and every chance they get they’re staring longingly out the window at the ocean, even though they apparently can’t swim. They also haven’t seemed to stopped what they are looking for, even looking around Muse A’s house, for what it is they can’t recall.
It almost reminds Muse A of the stories the old fishermen in town tell of Selkie. Seal creatures, doomed to live on land and wed the person that takes their pelt, never return to the sea, until they find it again. But that’s just a fairy tale.
Option 2) Muse A steals the pelt on purpose, seeing the sea beauty in the waves, and enthralled wanted to keep them for their own.