Dear Boyfriend:
Hello!
I am Zhu Qingyue.
I know at this moment you are probably seriously considering how to face Xing Jie, This must be the most frantic and uneasy time for you, right?
So I was thinking, what would happen if, at such a time, this letter fell into Xing Jie's hands and she saw it? Would it completely disrupt your pace? Would it obstruct your plans? Would it ruin the relationship among the three of us in an instant?
Just thinking about it makes my heart race, so I deliberately suppressed my shy feelings and put the term "boyfriend" at the beginning...
...Just kidding. I know this letter will reach you first.
Actually, I originally felt there was no need to write back. A love letter is a love letter, and by accepting it, I imply everything is OK. Everything that needed to be said has been said; there's nothing to add.
Unlike you, I don't feel that there are things that must be expressed through words in writing rather than spoken directly.