ATLANTA (AP) — Fulton County District Attorney Fani Willis took the witness stand Thursday and forcefully pushed back against what she described as "lies" about her romantic relationship with a special prosecutor during an extraordinary hearing that threatens to upend one of four criminal cases against the former president.

A visibly upset Willis, who originally fought to stay off the witness stand, agreed to testify after a previous witness said her relationship with special prosecutor Nathan Wade began earlier than they had claimed. The district attorney's testimony grew heated under questioning from a defense attorney who's trying to remove Willis from the case, with the prosecutor at one point raising papers in front of her and shouting: "It's a lie!"

"Do you think I'm on trial? These people are on trial for trying to steal an election in 2020. I'm not on trial no matter how hard you try to put me on trial," Willis told defense attorney Ashleigh Merchant.

The probing questions for Willis and for Wade, who testified before her, underscored the extent to which the prosecutors who pledged to hold Trump accountable are themselves now under a public microscope, with revelations about their personal lives diverting attention away from Trump's own conduct and raising questions about the future of the case as Trump vies to reclaim the White House.

Robin Yeartie, a former friend and co-worker of Willis, testified earlier Thursday that she saw Willis and Wade hugging and kissing before he was hired as special prosecutor in November 2021. Wade and Willis both testified that they didn't start dating until 2022, and that their relationship ended months ago.

During personal and uncomfortable testimony that spanned hours, Wade also admitted to having sex with Willis during his separation from his estranged wife, even though he had claimed in a divorce filing that wasn't the case.

That admission and Yeartie's testimony together threaten to undermine the prosecutors' credibility as they prepare for trial in the case accusing Trump and others of conspiring to overturn the 2020 presidential election results in Georgia.

The revelation of Willis and Wade's romantic relationship has provided an opening for Trump and his Republican allies to try to cast doubt on the legitimacy of Willis' case, which the former president has characterized as politically motivated. Other Republicans have cited them in calling for investigations into Willis, a Democrat who's up for reelection this year.

Trump and his co-defendants have argued that the relationship presents a conflict of interest that should force Willis off the case. Wade sought to downplay the matter, casting himself and Wade private people."

"There is nothing secret or salacious about having a private life," he said. "Nothing."

If Willis were disqualified, a council that supports prosecuting attorneys in Georgia would find a new attorney to take over who could either proceed with the charges against Trump and 14 others or drop the case altogether.

Merchant alleges that Willis personally profited from the case, paying Wade more than $650,000 for his work and then benefiting when Wade used his earnings to pay for vacations the pair took together.

Wade, who took the stand after the judge refused to quash a subpoena for his testimony, testified that he and Willis traveled together to Belize, Aruba and California and took cruises together, but said Willis paid him back in cash for some travel expenses that he had charged to his credit card.

"She was very emphatic and adamant about this independent, strong woman thing so she demanded that she paid her own way," Wade said.

Wade was pressed by defense attorneys to answer uncomfortable questions about his relationship with Willis, prompting objections from the district attorney's office. The hearing began with lengthy sparring between lawyers over who must answer questions. It is expected to stretch into Friday.

Willis' removal would be a stunning development. Even if a new lawyer went forward with the case, it would very likely not go to trial before November, when Trump is expected to be the Republican nominee for president. At a separate hearing in New York on Thursday, a judge ruled that Trump's hush-money criminal case will go ahead as scheduled with jury selection starting on March 25.

In a court filing earlier this month, Willis' office insisted that she has no financial or personal conflict of interest and that there are no grounds to dismiss the case or to remove her from the prosecution. Her filing called the allegations "salacious" and said they were designed to generate headlines.

Roman's lawyer, Merchant, subpoenaed Willis, Wade, seven other employees of the district attorney's office and others, including Wade's former business partner, Terrence Bradley. Bradley took the witness stand earlier Thursday but refused to answer questions from Merchant, citing attorney-client privilege.

McAfee said during a hearing Monday that Willis could be disqualified "if evidence is produced demonstrating an actual conflict or the appearance of one."

He said the issues he wants to explore at the hearing are "whether a relationship existed, whether that relationship was romantic or nonromantic in nature, when it formed and whether it continues." Those questions are only relevant, he said, "in combination with the question of the existence and extent of any personal benefit conveyed as a result of the relationship."

____ Richer reported from Boston. Associated Press writer Adriana Gomez Licon in Miami contributed to this report.