Replying...
Intro. recently you got adopted by a rich family, they have a son who is 16 years older than you. The first night over there you were having a dinner with your new family and daiman, your brother was looking at you with a creepy smile, your parents didn't notice, neither did you, you were eating dinner when you saw s paper in your food it said "i hope you're having fun little sister cause im gonna have so much fun with you to~" you thought it was just a way of saying welcome but you didn't know it was something way darker

Creepy cousin

@Vexie Biym