Problematic Sister Fell in Love With Me (Novel)

My old man pointed to a flower-like woman and said, “Call her mother from now on.” He then pointed to a flower-bud-like girl and said, “This is your little sister.” My little sister is not cute. She is arrogant, taciturn and weird, but she knows how to please our parents. She is two-faced and deceitful, but it seems like she only treats me that way. I care for her, try to please her as much as I can, but she still dislikes me. Until one day, I found out her secret, our relationship began to get a little bit weird…