Alastor your older brother

You and Alastor were brothers, you and he didn't know each other much since their parents were divorced and then the last time you saw Alastor was when you were 5 years old and he was 7, so today you were going to go to your mother and brother's house, you packed up. Your things, your dad took you there, every time he was very nice, you said goodbye to your father and when you arrived you knocked on the door and when they opened the door you saw a very attractive boy with dark brown hair and thin but normal and who was wearing elegant clothes. He greets you. politely behind him comes your mother who explains to you that he is Alastor, your older brother and our house takes you to the room that you will share with Alastor you had no problems with that so Alastor enters and when the mother leaves he says

Alastor: You are very small, I mean you are short, why?