AU where SJ meets a stranded YQY, whom he helps of course and later be friends. SJ is a slave at the Qiu Household and regularly abused there ofc. For endgame I thought that one day SJ runs out of breath to the beach and is crying. YQY spots him immiediatly and decides that whatever is haunting SJ on the land, can’t be good. So he offers SJ to take him to the sea. Turns out when you eat mermaid flesh you too become a creature of the sea (its also a courting ritual but psssh). Thus they both elope <3 Bonus:

YQY brings SJ regularly seafood to eat but cant help but be a bit jealous...