His confession to Hillary Clinton came two days before Clinton was to testify before a grand jury in August 1998 in an investigation that would lead to his impeachment, he said in an hour-long interview that featured emotion-laden visits to his childhood haunts in Arkansas.
"I had a sleepless night and woke her up and sat down on the side of the bed and just told her. And it was awful," Clinton said. The interview was the first to air on television to promote the book My Life.
"She looked at me as if I had punched her in the gut," Clinton wrote. The renewed focus on the White House sex scandal may be starting to test Clinton's patience.
Clinton has kicked off a full-throttle publicity campaign to sell his 957-page memoir, which goes on sale today.
The launch includes high-profile interviews, a lavish book party for a thousand guests in Manhattan yesterday and nonstop book signings and television appearances throughout the week.
While publisher Alfred A. Knopf has received more orders than the 1.5 million copies of the book's first printing, early reviews were tough on the former president's effort.
In a front-page review, The New York Times called it "sloppy, self-indulgent and often eye-crossingly dull - the sound of one man prattling away."
"In many ways, the book is a mirror of Mr. Clinton's presidency: lack of discipline leading to squandered opportunities; high expectations, undermined by self-indulgence and scattered concentration," the Times wrote.
Clinton described the book as unprecedentedly revealing.
"I think I've honestly tried to say more about my life than I believe any public figure ever has," he said in a television interview. "And probably more than anyone ever should."
The memoirs touch on everything from poignant childhood memories to glitzy meetings with heads of state to sleeping on a couch after his wife learned of his affair with White House intern Monica Lewinsky.