A crooked restaurateur testified Tuesday that he had “clear” and “unambiguous conversations” with Bill de Blasio about making illegal contributions to his campaign — and that the mayor ignored repeated warnings that what they were doing wasn’t “kosher.”

During his second day under cross-examination at the corruption trial of former Nassau County Executive Ed Mangano, Harendra Singh said de Blasio was fully aware the eatery owner was funneling cash into his political war chest with the help of others who took credit for the donations.

Mangano defense lawyer Kevin Keating asked Singh if he had “unambiguous conversations” with de Blasio about what he was doing.

“Yes, I had, regarding the straw donors,” Singh said.

“At one point, did you say to him, ‘These transactions are not kosher?’” Keating asked.

“Yes, twice,” Singh answered.

Singh also answered, “Yes,” when Keating asked him whether those were “clear conversations,” but didn’t specify when they took place or what office de Blasio — formerly public advocate and a city councilman — was seeking at the time.

The revelations in Central Islip federal court came hours after First Lady Chirlane McCray tried to blunt Singh’s earlier, damning testimony by insisting that her hubby was “such a Boy Scout” that he’d never break the law.

“I am fortunate in that I married a Boy Scout,” McCray said with a laugh on the Gotham Gazette’s “Max & Murphy” podcast.

“He is such a Boy Scout. He didn’t do anything wrong. I know he didn’t do anything wrong. He knows he didn’t do anything wrong.”

A de Blasio spokesman Tuesday said the mayor was never an actual member of the Boy Scouts of America, but Hizzoner did call on the youth group to lift its ban on gay adult leaders shortly before it did so in 2015.

McCray tried to downplay the extensive media coverage of Singh’s testimony by suggesting it was driven by sensationalism.

“I think that’s tabloid news,” she said.

“I think it comes and it goes. There’s always something, if it’s not play-to-pay it will be something else. That’s just the way the tabloids, specifically, how they operate.

“It’s always about taking something and how you pull somebody down. If there was anything to it you all would know by now,” she added with a laugh.

Singh’s Tuesday testimony came after he earlier told jurors last week that de Blasio had encouraged him to make straw donations to political cronies, including US Rep. Yvette Clarke (D-Brooklyn), who on Monday said she would donate $2,000 she got from Singh in 2012 to charity.

Singh also said Monday that de Blasio was among the pols — including Mangano — to whom he steered illegal contributions.

Singh is testifying against Mangano as part of a deal with the feds in which he secretly pleaded guilty to eight felonies, including bribing de Blasio with campaign cash for a “favorable” lease extension on his since-shuttered Water’s Edge restaurant in Queens.

De Blasio — who wasn’t charged last year following an investigation by the Manhattan US Attorney’s Office — has adamantly denied being bribed, saying Singh “agreed to certain charges for his own self-preservation.”