Ensign met with the husband of the woman involved and had what this source described as a positive encounter. But the source said that the man subsequently asked Ensign for a substantial sum of money – at which point Ensign decided to make the affair public.
Fun fact: Ensign is the Senate's only Pentacostalist and was a Promise Keeper. Remember them?
Conveniently, the source told Politico that the affair began while Ensign was separated from his wife, with whom he later reconciled. After healing his marriage, Ensign "gave the aide a severance package and parted ways." Class act. If this is the transparent lie that it appears to be, it will presumably come out fairly quickly, since Ensign's camp is saying the alleged separation lasted nearly a year.
Ensign is the head of the GOP Policy Committee, and the Washington Post calls him "a rising star in the Republican Party considering a 2012 presidential bid." But that's a bit much, given the fact that he ran the National Republican Senate Campaign Committee during the last election cycle, which was an unmitigated disaster for the GOP.
UPDATE: The Associated Press reports that the staffer Ensign was banging was married to another staffer. She worked for his PAC and campaign, and her husband worked in his Senate office. So when her husband demanded hush money, that was a Senate staffer trying to extort a sitting Senator, which one would imagine the Justice Department might be interested in.