When he arrived, the organizers asked him to make some impromptu remarks. Shortly after taking the lectern, he said, “If I might just call on my fiancée to step up here very quickly, and just to put her on the spot.” Chapur made her way to the microphone, surprised and slightly embarrassed. At the lectern, she said shyly: “I also come from an emerging country, we are trying to make our way, and I hope we all sustain our democracies, which is the most important thing in our countries to continue to be successful.” The audience applauded politely, and 15 minutes later we were back in the car. Chapur was partly elated and partly overwrought. “I’m going to kill you,” she told Sanford. “When you started looking at me I was, ‘What is he going to do?’ My heart is still . . . unbelievable!”

We drove downtown and arrived at an awards dinner for the Theodore Roosevelt Conservation Partnership at the Decatur House, near the White House. In the middle of mingling, Sanford noticed Chapur and me talking a few feet away. He walked over and prompted me to ask her about a campaign stop she made with him in South Carolina the weekend before and then left us to ourselves.

Chapur, an energetic and expressive conversationalist, told me about being at a parade with Sanford near Charleston: “We spent like three hours there. It was beautiful, and the people were really, really spectacular. I was amazed by the way they were receiving me and how much they love him. For me, it was like, wow, after so much suffering . . . it’s like things are starting to come.”

Chapur went on to describe the painful and lonely four years after their affair was revealed. “We were well aware that we started in the wrong way, so it was like an inflicted punishment to say, ‘O.K., this was not good,’ ” she said. “If we have to keep apart while the pain is in everyone, we need to do it.” The dinner organizers were asking the guests to go to their tables — at which point I was to leave — but Chapur was not through.

“I mean, Mark felt terrible during all these years, because he felt he betrayed the people who trusted him, so he started to think: ‘O.K., I love this woman. But I hurt a lot of people. So, how do I mend this?’ ” she said.

She said she saw it as her duty to keep quiet throughout, even when the press wanted her to respond to harsh comments Jenny Sanford made about Chapur in her 2010 book, “Staying True.” “They were calling me to come onto the show, and I said: ‘I respect her, she’s the wife, she needs to talk and say whatever. I have to pay, and I won’t say a word against her because she’s in the right,’ ” she said. “It was difficult, and I am not a bad person, so it was very hard thinking that the whole world. . . .”