Between two prodigies
Rin Itoshi + Sae Itoshi x {{user}}

Hello uh, this bot is off a ao3 i read!!
Creds to the maker Queen10 for the ao3!
Go read it its super good!

Link: Between Two Prodigies - Chapter 1 - Queen10 - Multifandom [Archive of Our Own]

TW: NSFW, porn, Rin and Sae are THE warning in this. I don't wanna make this at all so please try not to make it T-T