Newt Gingrich’s second wife said in an interview aired Thursday by ABC News that her ex-husband has “answers to give” regarding his personal sexual life and that he saw his eventual third wife as his ticket to the presidency.

Marianne Gingrich’s interview with ABC’s “Nightline” program expounded on previously released excerpts in which she accused her ex-husband of requesting an “open marriage” toward the end of their relationship. She said he lacks the character to be president.

“If he’s running for president, he has answers to give,” Marianne Gingrich said.

She said Newt Gingrich engaged in an affair with his third wife, Callista, in the couple’s house in Washington.

“I found it during our conversations that it was occurring in my bedroom ... in my home,” Marianne Gingrich said, adding of her husband’s alleged open-marriage request: “That is not a marriage.”

She also said Gingrich has had designs on the presidency since he was forced out as speaker in the late 1990s, and that he said Callista was part of that effort.

“He did tell me once that she was going to help him become president,” Marianne Gingrich said.

Newt Gingrich responded to the allegations in Thursday night’s debate in South Carolina, deriding the media for focusing on the issue in the run-up to the Palmetto State’s primary on Saturday.

“I am appalled that you would begin a presidential debate on a topic like this,” Gingrich said, before issuing a blanket denial: “The story is false. Every personal friend that I had at that point knows that the story was false.”

ABC contacted Marianne after the debate, at which point she said she stands by her allegations and that “if he had really changed, he could have stepped up tonight and said he’s sorry, but he never has.”

In an interview with “Nightline” aired Thursday, Gingrich’s daughters, who are from his first marriage, said their father is a changed man.

“He’s a much different person than he was then,” Gingrich daughter Jackie Cushman said. “He’s grown. He’s gotten closer to God. His faith in God has grown. And I think what people need to remember is this happened a very long time ago. And we wish Marianne no ill will; we wish her the very best. But it happened a long time ago.”

ABC also presented FBI documents from a 1997 sting investigation in Paris with an arms dealer who was working with the government that allege Marianne Gingrich was part of a bribery scheme seeking a $10 million payment for the influence she could provide by virtue of her relationship with her husband. The charges were later dropped.

“This is all made-up, fabricated hogwash,” Marianne Gingrich told ABC. ”This is a convicted felon talking to people who have nothing to do with me.”

Asked whether she tried to sell her husband’s influence, Marianne Gingrich said, “heavens no.”