THEY WERE like flint striking steel, but the sparks of anger and mistrust that flew off resulted in a smoldering, but rocky relationship challenged by misunderstandings and suspicion, and later obstinacy. Cate, 38, the elegant and sophisticated Presidential press aide, and Gus, 26, the handsome, rough-edged, bright young and freewheeling White House reporter were the perfect mismatch, in age and outlook. However, the embers burst into flame and eventually consumed them both when a May-September unexpected love resulted. Nevertheless, the flames threatened to become the funeral pyre of their relationship when ambition and distance cooled their romance and threatened its very existence. But it was the President of the United States that, unknowingly at first, changed all that and a gave a less-than-fairy tale romance a fairy tale ending that you will never forget long after the last page is read.