The mysterious five-day disappearance of South Carolina Governor Mark Sanford fueled a lot of speculation this week. Monday night, his office said he was taking a hike on the Appalachian Trail. This morning we learned he actually took a trip to Buenos Aires, Argentina. And by Wednesday affternoon, Sanford revealed he went to Argentina over Father's Day weekend to visit a woman he began having an affair with a year ago. WFAE's Greg Collard reports. Sanford began his press conference by acknowledging there's a larger story to his mysterious disappearance. He said he was going to lay it on the line. Boy, did he. "The bottom line is this. I've been unfaithful to my wife. I had developed a relationship with what started as a dear, dear friend from Argentina," Sanford said to reporters at the state capitol. He said he met his mistress eight years ago when she was separated from her husband. At the time, he said he advised her to reconcile with her husband for the sake of her children. Over the years, Sanford said an e-mail relationship ensued. "About a year ago, it sparked to something something more than that. I've seen her three times since then during that whole sparking thing," he said. Sanford didn't identify the woman, but said his wife and children became aware of the affair five months ago. He said he and his wife have been in counseling. Sanford went on vacation last Thursday. He dismissed his security detail and didn't let his staff know where he was going. Late Monday night, the governor's spokesman released a statement saying he was hiking the Appalachian Trail. Sanford acknowledged he misled his staff about his whereabouts. He also said his staff didn't know about the affair. In the last several months, Sanford's resistance to accepting federal stimulus money gained him respect among many fiscal conservative. He's been mentioned as a Republican presidential candidate in 2012. But at his press conference, Sanford said he'll resign as chairman of the Republican Governors Association and give his attention to his wife and children in what he said will be a long process. "I would say to Jenny, anybody who has observed her over the last 20 years of my life knows how closely she has stood by my side in campaign after campaign after campaign, and literally being my campaign manager. And in raising those four boys and in a whole host of other thing throughout the lives we have built together," Sanford said. But unlike so many other press conferences in which politicians confess their marital sins, Sanford's wife was not by his side.