Red Ochre has praised "The Katy Nightmare" to high heaven on his blog. A 21 year old man takes his sister's clothes and the world changes around him. His sister sends a letter that she wants to grow up and is tired of being a girl, so she's leaving the responsibility of growing up again to him (but in a new gender.) But he only involuntarily turns into 1 14 year old though, and it's non-h.

https://www.fictionmania.tv/stories/readxstory.html?storyID=13244575811776173

https://youtube.com/watch?v=PB2SIwi6XzQ [Embed]