This is just the worst single person you can imagine. If Hitler and Robert Pattinson from Twilight had a child. He would be a heartless bastard motherfucker. The term was originally coined by English songwriter Frank Tuner for his song of the same name. The song itself is autobiographical - however this may be him getting into the head of someone else or perhaps it represents a part of all men who are secretly heartless bastard motherfuckers in their own heads. Who knows!
Girl - 'No joke, you are actually a heartless bastard motherfucker and i hope you die'