Son of Krypton, Daughter of Earth
22 parts Complete ONC 2021 Fanfiction prompt 13 and Romance Prompt 71.
This novella is a non-canon version of Superman, with some of the same characters and places.
Lexy Logan is sent from an Earth like ours where Superman is a fictional character to one where he is a real man, Clark Kent. Clark befriends her and helps her live in his world until she has to leave. She falls in love with Clark and tries to hide her feelings to protect them both, but he falls in love with her, and can't hide his feelings, but they accept what they can share until she must leave.