Last Night

Last night my father received an SMS from Mary, who happens to be my stepsister (whom I have never met b4). The way she texted was like she was very close. It went something like "Dad, can we go out for dinner on another day? Coz I got studies on Thursday." and something else about buying a harddrive, but that's not important. It's juz so unfair that she is so close to him although he is not officially her father anymore, but mine...and yet my father is hating me so much...feeling depressed...