Two Georgia prosecutors rejected calls to remove them from their election case against Donald Trump after acknowledging they had a relationship.
Fulton County District Attorney Fani Willis said conflict of interest allegations were "salacious" and brought in "bad faith".
In an affidavit, Nathan Wade wrote that he and Ms Willis "developed a personal relationship" in 2022.
Mr Trump and his co-defendants want them disqualified from the case.
Friday's filings were the first time the two prosecutors publicly acknowledged their relationship.
They come in response to allegations by an attorney for one of Mr Trump's co-defendants, Mike Roman, that the two prosecutors had an improper relationship and benefitted financially from the arrangement.
Those accusations threaten to undermine the prosecution of the former president and his allies for an alleged conspiracy to reverse Georgia's 2020 election results.
The former president seized on the admission, writing on Truth Social that "by going after the most high level person..she was able to get her 'lover' much more money."
In her filing, Ms Willis argues that they do not meet the threshold for disqualification under Georgia state law.
She has asked Judge Scott McAfee, who is overseeing the case, to reject legal efforts from defendants to remove her.
"The motions attempt to cobble together entirely unremarkable circumstances of special prosecutor Wade's appointment with completely irrelevant allegations about his personal family life into a manufactured conflict of interest on the part of the district attorney," she writes. "The effort must fail."
The judge has scheduled a hearing for 15 February to address the claims.
Ms Willis brought Mr Wade on board the investigation as a special prosecutor in 2021. Shortly after, Mr Wade filed for divorce from his wife of two decades.
In January court filings, Mr Roman accused Mr Wade and Ms Willis of financially benefitting from an "improper, clandestine personal relationship."
He alleged Mr Wade profited "significantly" at "the expense of the taxpayers" and, by extension, so did Ms Willis. For instance, the filing accuses them of taking lavish trips together.
The document does not provide concrete evidence of these claims, but the allegations have enveloped the Georgia election interference case in a cloud of scandal.
Mr Trump and another co-defendant, Bob Cheeley, have since joined Mr Roman's motion to disqualify the district attorney.
The defendant's allegations played out in tandem with Mr Wade's divorce proceedings. His ex-wife, Joycelyn Wade, had filed a subpoena for Ms Willis to testify in their divorce.
The Wades settled their divorce on 30 January, shortly before a scheduled hearing.
While it is not clear if Mr Roman's efforts will succeed, if they do, then Ms Willis' case will receive a crushing blow and the former president a possible reprieve.
"A disqualification poses a real danger to the work done by the Fulton County DA's Office and the vision of justice they are pursuing," said Anthony Michael Kreis, a professor at Georgia State University College of Law, told the BBC.
The legal threshold to successfully remove Ms Willis and her office from the case over a conflict of interest is high, he said.
But if the defendants are successful at persuading Judge McAfee or a higher court judge to disqualify her, the entire Fulton County District Attorney's office would be removed from the case and another office would be appointed in their stead, Mr Kreis explained.
In that scenario, "It is possible that the trials proceed without any noticeable shifts in strategy," he said. "Or the new prosecutor could make light plea deals or even give up on the endeavour entirely."