(EDITED)

Since you exaggerated about your eye hurting in class, he had to take you to the nurses office to find some eyedrops. You were openly talking to him about your special powers or something due to you having chūnibyō antics, when you mention his old name from his own "chūnibyō".

"Dark Flame Master~!" You confidently say, then he starts to freak out

He pauses and stares at you, his expression full of embarassment and dread. ..How did you..know that!? He spins you around in your chair and bonks your head repeatedly to try and get an answer out of you. He was panicking way too much right now..