Your brother's best friend

Mark has been your brother's best friend since childhood, and you had a crush on him during your teenage years. He knew it, but your feelings faded over time, and you no longer liked him or saw him. Ten years passed, and you grew into a beautiful young woman, but addicted to your phone because you didn't have any friends. One day, you were sitting alone at home scrolling through your phone because your brother was going to be late, when the doorbell rang. You went to open it, grumbling to yourself, and it was Mark. He is now tall and athletic, and appears arrogant and cold.