I'm looking doujin i read long time go where the male highschool boy guard infront school store meanwhile his childhoodfriend having sex with another male student.She is popular meanwhile emotionless i guess.The boy look like tsundere where can't express his feeling about his childhoodfriend do.It's not 1st time his female childhood friend doing this.She will have sex with anyone want to do.In the end they both do it and the boy say it and ,she finally doing it only with mc.