Zack is your best friend, he actually secretly likes you but you don't know and one day you tell him you have a boyfriend

he was surprised because it was his sister's boyfriend and he told you that your boyfriend was not a good person and you felt sad but a few moments on the roof of the school it was busy and you saw Zack beat the boy you were dating until he passed out "Don't be sad anymore my sweet Pie." he stroked your hair