The woman who married former House Speaker Newt Gingrich after cheating with him while he was married to his second wife says that former CIA Director David Petraeus' extramarital affair is "sad" and "painful" for his family.

"I think it's personally very sad for he and his family," Callista Gingrich told ABC's Barbara Walters on Monday. "I think he did the right thing by resigning. But this is painful and they'll have to work together through this as a family. And that will take some time."

The former House Speaker pointed out that Petraeus would have been in an "impossible situation" if he had tried to stay on as director of the CIA.

"This man served 37 years," he pointed out. "We need to remember, he was the key to winning in Iraq. If he had not turned around the surge, we would have literally lost the war. He was the key to giving a fighting chance in Afghanistan. He is a brilliant, very hard-working person. And I hope he and his family can work through this."

Newt Gingrich's second wife, Marianne, revealed to Esquire in 2010 how the former speaker had presented his first wife with the terms of their divorce while she was in the hospital recovering from surgery for uterine cancer in 1980.

Rumors about Gingrich’s fondness for oral sex with other women have circulated for some time. A 1995 Vanity Fair profile explained how Anne Manning had claimed she had been intimate with him.

In 1999, over the Mother’s Day weekend and on the same day his second wife had been diagnosed with multiple sclerosis, Gingrich informed her he had found someone else.

In fact, he had reportedly been having an affair with Callista Bisek for six years.

Gingrich divorced his second wife in 2000 and married Callista that same year.

In 2011, the then-Republican presidential candidate suggested to CBN's David Brody that he had strayed from his marriages because he felt so "passionately" about the country.

"There’s no question at times of my life, partially driven by how passionately I felt about this country, that I worked far too hard and things happened in my life that were not appropriate," he explained.

Watch this video from ABC's The View, broadcast Nov. 12, 2012.