Like something straight from a drama. The lead female tries to find the good in the leading male but he's too wrapped up in the bad boy act and leather jackets. "No...im a bad person" with that smug look on his face. Then he bumps past her to go prove his point with a terrible act of some sorts
Sound like when someone is either trying to impress their crush by stating that they are "bad" too or when someone tries to convince someone they shouldn't go out on a date at all, because the person don't like them.