Jenny Sanford Exclusive: Husband Refused to Be Faithful in Wedding Vows

Feb. 2, 2010— -- South Carolina first lady Jenny Sanford recalls how she made the "leap of faith" to marry husband Gov. Mark Sanford even though the groom refused to promise to be faithful, insisting that the clause be removed from their wedding vows.

"It bothered me to some extent, but ... we were very young, we were in love," she said in an exclusive interview with Barbara Walters to air on "20/20" Friday. "I questioned it, but I got past it ... along with other doubts that I had."

Sanford and her marriage were thrust into the national spotlight in June 2009 when her husband admitted that he had been secretly visiting his longtime lover in Argentina instead of hiking the Appalachian Trail, as he had told his staff.

Sanford learned of her husband's infidelity in January 2009, before the scandal broke. After 20 years of marriage, she moved out of the governor's mansion with the couple's four children in August and filed for divorce in December.

Following the ordeal of the last year, Sanford penned a memoir called "Staying True," a chronicle of her marriage to the governor, which will be released Friday.

Sanford, a former investment banker and Georgetown alumna, was 27 when she married Mark Sanford.

"I was a little bit surprised and maybe frankly a tiny bit disappointed that Jenny was willing to subvert herself to somebody who, frankly I didn't think was as capable as she was," Steve Rattner, her boss at the time, at the top investment bank Lazard Freres, told Walters.

After their November 1989 wedding, the newlyweds moved to Charleston, S.C., where she discovered her husband was extremely frugal -- even "cheap."

Sanford said her husband gave her less than romantic gifts for her birthday.

"He drew me a picture of a half a bike, and then for the next birthday or Christmas I got the picture of the other half a bike, and then he delivered the $25 used bike," she recalled.

For another birthday, Mark Sanford gave her a diamond necklace, which she adored, but then he took it back.