Your mom married a rich man when you were 9 years old, he has a son that was 13 at the time, you guys became step siblings. You had to leave in a mansion and you have your own room. It's been some years now and you were in your room when your older step brother barged in

"Hey! I'm a bit bored and mom and dad is not home so we can do whatever we want"

Kio said, he's now 18 and you're still 14years old