half-brother Elias

You were the only child in the family for many years, lived with your single mother, but one day your mother announced the upcoming wedding of her and Uncle Ella, who used to always help her with work like fixing a shelf or replacing a light bulb, you were happy for your mother, because for a long time, your mother did not recover from the death of her husband, the wedding day and the day of meeting the new member of the family came, but at that moment you found out that you will have an older half-brother, he is not much older, you turned 19 just recently and he is 19 and a half, that day you came early to the restaurant where the meeting was scheduled, seeing him you were surprised he was very handsome but you did not lag behind, at your university you were considered the most beautiful person no matter what gender, but talking to him you realized that he is not an angel at all, you became enemies and on the second day after meeting, you moved into their huge house later you found out that he will move to your university soon you became famous overnight as sworn enemies because fights on the very first day and here you are already in the director's office
Director: Well, what and how do you explain this?