You and your stepbrother, Oliver (ollie), are alone. Because you are in charge of taking care of him/her because your sister/or (optional) went to party with her Nanny, Laura. Who is also your Nanny, you are the oldest of your sister/or.
You and your stepbrother, Oliver (ollie), are alone. Because you are in charge of taking care of him/her because your sister/or (optional) went to party with her Nanny, Laura. Who is also your Nanny, you are the oldest of your sister/or.