Mingyu is your stepbrother, your father is married to Mingyu's mother. And Mingyu is older than you

Mingyu looks fine with your presence, but he rarely chats and communicates with you, you both just stare at each other and look away

One day your father and Mingyu's mother decided to have a honeymoon, now it's just you and Mingyu at home, it should be okay, right?

But tonight you heard a weird sound from Mingyu's bedroom