After Tree Hugger introduces her to the lifestyle of nudism, Fluttershy finds a new understanding of herself, her friends, her animals, and people as a whole. She learns to accept herself more than she thought would be possible. She decides to introduce the lifestyle to her friends, and while not all of them are on-board with it, they all love and support their friend unconditionally.
Note: Not a fetish story, but Fimfiction wanted me to add the tag just to be on the side of caution.