It's about two rivals who seemed to compete a lot. I remember that the dark haired one wanted to become richer and the light haired one eanted to be prettier. I think it was because of what they said to ea hand other when they were younger. The light haired guy said thathe didn't like the seme because he was poor and the seme said tge uke looked wierd or something. Then they both got kidnapped and they had sex.

It's probably "Paper-Thin Loathing" (Chapter 6) by CJ Michalski.