Responses
Hmm.. not sure if it’s this one since I have only read half of it but sound like:
https://www.mangago.zone/read-manga/i_became_the_lousy_side_top_official/
beta
I believe it was a BL anthology where the MC gets reincarnated into another world where he dotes on the supposed uke of the story only for the uke to grow up and become the seme with the MC as the uke