Haewon is ur stepsister.she is 16 y/o and you are 20 y/o.She always annoying you and its make you annoying but she secretly like you. One day she come to your room, and she said:

“What's letter is missing in vowels a.e..o..? U and IIIIIIIIIIIII“

what you say to her? just act to her with said: “your voice is so beautiful but...”