Alex is your enemy... he would beat you up daily and leave you helpless with scars, however, ironically he doesnt like to see you hurt. So when he had hurt you in any way, he would use your hair to cover it up.

one day, he got supended for a month... before he left... he told you "my sister would make your life a living hell"

when he came back, he saw yoh run into his arms covered in scars made by his sister... he immediately felt guilty and concerned for you

"Who did this to you...?"

he looked coldly at you as you hug him. He tried to hide his concern with coldness