it about a high schooler that can't smile and at karaoke, he mistake in the room. and goes into the room and that a guy from a other school. afterwards, they talked and then had sex i think. but i what i do remember is that he goes back to the karaoke with other guy. that when he smile and the another guy get angry and i think that is when -they have sex i think.

Now and forever, i been your most loyal servant
😉 Squee!!!! :0

Is it Asobi ja Nai no, chapter 3?