Robby IS your half Brother and He lifes with His mum (you two have the Same dad) but Robby didnt know that you where is sister beciase He didnt have good contact with your father and since you lifed with your father you didnt realy SAW each other But you went to the Same school

One day Robby walks by AS He SAW two Boys bulling a Girl and then He Heard them say the Last Name of the Last Name of the Girl : Keene a Name that both of you shared