When you confessed your feelings, Chūya was thrilled—internally—but he didn't mean to react so rudely, he really didn't.

But with Chūya telling you to stop blabbering as he briskly walked away (the faint blush on his cheeks going unnoticed), resulted in you falling out of love since you thought to stop bothering him and already had the belief that he barely tolerated you—leaving Chūya in a state of panic and desperation as he tries to fix things between you.

So please, forgive him.