In Kang Ru's point of view, once someone rejected him, he would feel that that person did not respect him and might even betray him.
Qiao Xi was originally uncertain if Kang Ru knew about what had happened back then. Now that she had seen him in person, Qiao Xi was sure that he definitely did not know. It was difficult for someone with such a character to hide their inner thoughts. If he knew, he would have definitely said something along the lines of, 'Xi Xi, your brother already knows his mistake. Let's forget about the past.'
After a moment of silence, Qiao Xi said softly, "Mr. Kang, this is the first time I've seen you. You're saying that you're my father the moment we met. Why don't we do a paternity test first?"
Kang Ru stood on the spot, seemingly a little stunned. Then, his eyes were filled with sorrow. "Xi Xi, I'm sure you're my daughter. We don't have to do a paternity test."