A former aide to John Edwards testified Thursday about an unexpected pronouncement from a campaign videographer: She and the presidential candidate were in love.

But Edwards later told him he was not in a relationship with Rielle Hunter, John Davis said.

"He told me she was crazy and that he denied there was an affair," according to Davis. The assistant said he took Edwards at his word.

Jurors on Thursday also heard from an interior designer who served as the conduit for hundreds of thousands of dollars of alleged coverup money from a wealthy Edwards benefactor. Bryan Huffman testified that neither he nor the donor knew that the money was to be used to conceal Edwards' extramarital affair with his mistress.

Prosecutors say Edwards broke federal law by accepting about $725,000 from heiress Rachel "Bunny" Mellon and more than $200,000 from Fred Baron, a now-deceased Texas lawyer who was his finance chairman.

The money was used to pay for Hunter's living and medical expenses, travel and accommodations to keep the mistress out of sight while Edwards made his second White House run in 2008, prosecutors say.

Edwards is accused of hiding the money from the public and the Federal Election Commission, which polices political contributions, by filing false and misleading campaign disclosure reports.

Davis' testimony was the latest from Edwards staffers about their former boss's relationship with Hunter. Edwards, who was married at the time, eventually admitted to having carried on an affair with the woman and fathering her child.

A former campaign staffer said Thursday that Edwards flatly refused to sign a document in December 2007, under penalty of perjury, declaring that he was not the father of Hunter's child.

Mark Kornblau testified Edwards had been told that if he signed the affidavit, the National Enquirer might consider not running a story about his affair with Hunter.

Legal experts say that by refusing to sign the document, Edwards demonstrated that while he was willing to lie in public about the affair, he was not willing, in this instance, to break the law.

Prosecutors reacted with surprise to the testimony, asking the witness why he never told them about this in pretrial interviews.

Kornblau's response: Prosecutors never asked about the matter.

Davis, the former aide, testified he was surprised to see Hunter at a Detroit hotel in February 2007 because he thought her work as videographer had been completed.

The two exchanged pleasantries in the lobby.

Davis said he rode the elevator for a few floors with Hunter before getting off to avoid a longer ride with her.

"I would have preferred not to have seen her," Davis testified.

Minutes later, Hunter knocked on his door.

Hunter, according to Davis, "told me that she and Sen. Edwards were very much in love" and the candidate was concerned because Davis had seen Hunter in the hotel.

The aide testified he told Hunter that "I did not care about this because I was focused on the campaign."

Davis also testified about a phone conservation involving Edwards after a September 2007 appearance on CNN.

Edwards was talking with a woman whose voice sounded like Hunter's, according to Davis.

Edwards asked the woman on the phone, "Can you tell if you are showing?" the witness said.

Earlier testimony indicated Hunter believed she became pregnant in early May 2007.

Davis also suggested that Edwards came close to pulling out of the race after an argument with his wife, Elizabeth Edwards, who has since died. The candidate instructed Davis to pull together a conference call in which Edwards was to announce he was suspending his campaign.