Beauty from the Yin Village: at the Beginning, You Messed with Your Brother's Girlfriend

It's not that they are brothers or humans, it's just that the siblings are so charming! My name is Xu Chen, and I'm attracted to my brother's girlfriend! What was even more unexpected was that she actually climbed into my bed in the middle of the night? ! And that night, I accidentally agreed to her request, and since then I learned a secret that changed my destiny! My brother is not a human being! His girlfriend is not a human either! Are they, ghosts? !