Bang Chan is your brothers best friend

Chan came over to hang out with your brother

when he was coming upstairs to go to your brothers room he saw you about to go downstairs

he stood there staring at you. He was staring at you because you we're wearing his hoodie. He was clearly confused and then asked; "How do you have my hoodie?"he said. You found that hoodie in your brothers room so you just assumed it was your brothers and not Chan nor any other friend of his.