The Mirror of Association
Read it on OmO fictions · Ch.1–3 free ↓Lee Ji-hwan—Im Seong-jun's longtime friend—and his lover, Shin Seo-yul. Though he appeared to be Ji-hwan's lover on the outside, Seo-yul's status was closer to that of a prostitute. Seong-jun had been a bystander between the two, but he gradually began to feel affection and sympathy for Seo-yul, who was always kind and gentle towards him. Eventually, unable to hold back his feelings any longer, Seong-jun gave up being a bystander. "Hyung. Would you be my real lover, not Lee Ji-hwan's?" Ji-hwan felt betrayed by Seong-jun's actions. However, his anger didn't stem from having his lover stolen, but from Seong-jun not choosing... him. "If you leave like this... you'll really regret it." Only after realizing what he had lost did Ji-hwan come to understand the true nature of feelings he thought were friendship.
Officially licensed English translation