Do you think that Prats suddenly, just out of a blue, decided to tell him that she does not want to be his sister??? I do not think so, because if you watched BB carefully you would not think like this! First, if you call somebody your sister, it means that you love and respect that person, and are ready to protect that person. Asif did not protect Prats in none of the cases when she was attacked from other contestants or from Salman himself, he never protect her or support her, or console her, so he never acted like a brother! That is why she told him she does not want to be his sister, and now that is so horrible 😲that she said that. She simply did not feel that he is honest toward her, which he was not, so she reacted acording to situation.
In the beginning they sing and dance together, joke with each other, prepare the bengali dish together for other contestants, she was fair toward him (and I am sure he knows it, contrary to all of you who just see what BB want you to see). When he was hurt in one of the games and sitting all alone by the swimming pool she was the only one who comes to him to see how he was. So she must have good reason why she told him that she does not want to be his sister.
And now suddenly he gives her advice😲😕, if he was a friend, a brother, why he did not tell her that in the house, but he just repeat that what Salman told her on Saturday, that is why she did not accept his advice. And she has every right to do so.