President Donald Trump's lawyer in the Russia investigation is enmeshed in another high-stakes legal battle — against his estranged wife.

Rudy Giuliani was in state Supreme Court in New York on Wednesday, where a lawyer for Judith Giuliani claimed the former New York City mayor has spent over $900,000 since April while claiming he has financial difficulties.

Among the expenditures by "America's Mayor" were $12,012 on cigars and $7,131 on fountain pens over a five-month period, Judith Giuliani's lawyer, Bernard Clair, told Justice Michael Katz, according to NBC New York affiliate WNBC.

In that same time frame, Giuliani, 74, also spent over $286,000 on his alleged mistress, $447,938 "for his own enjoyment" and $165,000 on travel for himself, Clair said.

But since his wife filed for divorce earlier this year, Giuliani has claimed his income has dried up, Clair said, mockingly referring to the problem as "sudden income deficit syndrome."

That's "financial trouble that existed only post-commencement" of the divorce, he told the judge.

"His actions and his finances and his expenses don't comport with the claim of his income diminishment," Clair added, noting that Giuliani reported making $9.5 million last year.

Giuliani and his lawyer say he is representing Trump for free, and the court proceeding revealed what he has given up to take on special counsel Robert Mueller's investigation: from $4 million to $6 million from his former law firm, Greenberg Traurig, which he left in May.

Katz asked Giuliani why he would represent Trump for nothing, given that the president's other lawyers in the Russia probe are getting paid. Giuliani's lawyer, Faith Miller, said he was doing so because of "a 30-year relationship with Mr. Trump."

Miller maintained her client has been generous in supporting his wife, the former Judith Nathan, since their split, paying about $1 million in expenses. And, Miller noted, Giuliani has been working three jobs and is still making millions while the "much younger" Judith Giuliani, 63, "chooses not to" work.

While Giuliani's alleged fountain pen spending was a surprise, his fondness for cigars is well known. He once graced the cover of Cigar Aficionado magazine, which last year hailed him as "a stalwart defender of cigar rights." He's also a regular at the Grand Havana Club, an exclusive cigar smoking club in New York City, where membership costs over $7,500 a year.

Giuliani had an ugly and very public divorce from his second wife, Donna Hanover, during his second term as mayor. The case was settled in 2002, with Giuliani agreeing to pay Hanover over $6.8 million.