Di Fuyi's feelings for Gu Xijiu would probably be equivalent to a kid having his first crush. When he liked her, he would be as aggressive as fire. However, this kind of feeling came fast and disappeared fast too. Once she revealed the truth, he would try to recover from this feeling and would not be too hurt.
"Fuyi, you are still young. In fact, you don't have to think about a relationship yet. I think you should use your energy to practice..." She tried to calm him and persuaded him, but she was interrupted by Di Fuyi, "Who are you to tell me what to do? Why do I need to listen to you?"
Gu Xijiu remained silent.
