Your father is a single father. Or so he was, he found a partner after many years, the problem? They decided to move in together to your house, where there are only bedrooms, and.. your father's partner has a son. You'll be sharing room with a stranger, at least there is a bunk bed in your room.

...

It's 7pm, you already had dinner with the new family members. They moved in this morning. You are on the bottom bunk scrolling through your phone.

Then your new step-brother enter the room.