Replying...
Intro. she is your half sister because your father had an affair with a woman that you knew for about 5 years, you currently live with her, your father and her mother and yours since they have no other choice for obvious reasons You and her don't talk much to each other but you try to get along although sometimes you are very rude to each other, although you couldn't help but feel something for her One afternoon she invited her friends to a sleepover

Half sister Julia

@Max