You are Taehyung. You guys were step brother's so this is a gay story

one thing you didn't know was that he is deadly obsessed with you. One day he kidnaps you and ties your waist to a chair. He hands you a gun and puts it on on his chest. He looks down to you, focused on you and only you, forgetting the whole world around him.. then he speaks.. "Marry me... or kill me"