The moment Radia fell in love with him?
Han Joon tilted his head. They were already in a tight relationship at that point, deeply obsessed with each other. Radia had stopped seeing anyone else ever since he frequented Joon's bedroom, and naturally, Joon had thought he acquired Radia's heart at that point.
Seemed like that wasn't the case?
Radia chuckled when he saw the confusion in Han Joon's face, and he held the warm hand tightly. "I knew I had this weird obsession with you, the kind of attraction I had never felt with anyone else, but..." he smiled sheepishly. "It was hard to say we were in love at that age, wasn't it? I mean...normally."