That's right, they are Xiao Ming and Xiao Hong from the primary school mathematics textbook...
Xiao Ming: "Suddenly I discovered that my childhood sweetheart Xiao Hong took the wrong medicine and didn't speak according to her lines every day. What's wrong? QAQ"
Xiaohong: "..."
Xiao Ming: "Oh, no. I also found out that Xiao Hong, my sweetheart, is actually a man..."
Xiaohong: "Have I ever said that I am a woman?"
Xiao Ming: "Damn, what you said makes sense..."