In a trial where the role of mistresses – the defendant’s and even his lawyer’s – has at times fascinated as much as the glimpses into one of the world’s most powerful drug cartels, Lucero Guadalupe Sanchez Lopez did not disappoint on Thursday.

Sanchez Lopez, whose resume is an intriguing mix that includes being legislator from the Mexican state of Sinaloa, drug trafficker, and paramour of alleged kingpin Joaquin “El Chapo” Guzman, took the stand wearing a blue prison uniform. And shortly into her testimony, when asked what kind of relationship she and Guzman had, she delivered the line of the day: "Well, until today, I thought we were a couple. I'm confused."

That prompted Guzman’s wife, Emma Coronel Aispuro, who has sat impassively in the courtroom and attended nearly every day of the proceedings, to laugh.

At another point in the testimony, Sanchez Lopez she was 'trying always to keep him happy.” Her huge mistake, she said, was falling in love with the kingpin, who was 32 years her senior.

“I was confused over my feelings for him. Sometimes I loved him, and sometimes I didn’t.”

After years of denying any link to Guzman, the former Mexican lawmaker poured out the details of their relationship at his trial in Federal District Court in Brooklyn. She also described the elaborate steps she took to deliver and launder drug money when she joined the Sinaloa operation.

Sanchez Lopez said she first met Guzman in 2010, and became his lover in 2011, when she was just 22. That's also when she entered the drug world, she said. Her role in the Sinaloa operation, she said, was to “collect marijuana in the mountains of Durango, Sinaloa.”

Guzman told his young lover that he would have “no one else” handle the marijuana shipments.

Sanchez Lopez said she and Guzman would speak and text on phones that were swapped out every two weeks or so, to avoid detection. They saw each other up to five times a month. She would look for marijuana for her boss and lover in the states of Durango and Sinaloa, where in 2014, at the age of 24, she became its youngest elected lawmaker.

Sanchez Lopez said she sent packages of 10 kilograms (20 pounds) each so it could fit on a plane. “He would ask me for the ‘3 B's: Buena, Bonita y Barata” ('good, nice and inexpensive')," she said. She said the marijuana shipments she handled grew to more than 400 kilos.

On the witness stand, Sanchez Lopez cast herself as someone who at times felt afraid of Guzman, and sought to demonstrate her loyalty to him.

She said she told Guzman that she enjoyed the drug trafficking work.

“I like it. At least I feel useful,” she texted him once.

“I had my reasons,” she said in court. “First of all, so he didn’t think i would rat him out. I didn’t want him to mistrust me so he wouldn’t hurt me. Second, I didn’t want to have my siblings involved” as he had tried before.

Sanchez Lopez said she and Guzman lived together for a while and she was the “housewife.”

Sanchez Lopez pleaded guilty to federal drug charges in Washington D.C., after being arrested in the U.S. in 2017. She is awaiting sentencing and faces life in prison. Prosecutors are trying Guzman on 17 drug trafficking counts.

References to her came up in the accused kingpin’s trial peripherally during testimony about how Guzman allegedly managed to run his massive drug empire while also spying on his wife and various mistresses - including Sanchez Lopez.

The former legislator confirmed long-time rumors that she was with Guzman when he eluded authorities in Mexico in 2014. The drug lord evaded them by retreating into a tunnel in his Sinaloa home, then hooking up with other tunnels throughout the city.

Sanchez Lopez said that Guzman ran naked in tunnels for about an hour trying to escape the authorities.

'EL CHAPO' PAID MASSIVE BRIBE TO MEXICAN PRESIDENT, WITNESS SAYS

Charged in 2017 in a San Diego federal court with conspiracy to distribute cocaine, she was arrested as she tried to cross a bridge from Tijuana, reportedly to seek political asylum, according to the San Diego Union. Sanchez Lopez told authorities she feared for her life in Mexico, where she had received death threats.

A criminal complaint said wiretaps showed Sanchez Lopez was in contact with the cartel about delivering and laundering drug money. Although she vehemently denied in Mexico media interviews having any contact with cartels and even knowing Guzman, the criminal complaint for the San Diego case against her said that Sanchez Lopez admitted to having been his girlfriend to an informant.

Sanchez Lopez’s contacts with Guzman was long a subject of speculation in Mexico, where she made headlines after allegedly using phony identification to visit him in jail. She denied the accusation, but video footage from surveillance cameras at the jail showed her handing over the bogus documents.

In a 2016 satellite interview from Mexico with Univision anchor Jorge Ramos, Sanchez Lopez denied rumors that Guzman had helped her get the legislative post in Sinaloa. She also denied allegations raised by Ramos that she had become a major financial backer of the Sinaloa's drug operations. She refused to answer when Ramos asked her if she knew Guzman, saying that in time she would respond to the rumors.

Her government-appointed lawyer in San Diego, Francisco Verdugo, said to the San Diego Tribune that the arrest by U.S. authorities caught Sanchez Lopez by surprise. “Neither she nor we had any idea that she was under investigation,” in the U.S., Verdugo said. “If she had, she wouldn’t have gone there.”

Sanchez Lopez was only the latest onetime mistress to appear in the Guzman trial. Earlier in the proceedings, prosecution witnesses took the stand to reveal details of Guzman's phone calls and texts exchanges with different women.

“You are the most important person to me, I love you,” said one text to Agustina Cabanillas Acosta, who was allegedly both Guzman's mistress, and an active partner of his in the drug trade.

Witnesses also said Guzman relied on spyware to monitor the communications of his mistresses and his wife, who has been an active presence at the trial. Coronel is not allowed to visit with or have any direct communication with Guzman, out of security concerns.

Thursday's courtroom drama was just the latest in what has been an eventful week in the El Chapo trial. On Tuesday, a former associate of Guzman testified that former Mexican President Enrique Peña Nieto was paid as much as $100 million in bribes by the Sinaloa cartel before he left office last year.

Details of the alleged $100 million bribe came during the defense attorney’s cross-examination of witness Alex Cifuentes, who used to work as Guzman’s secretary. Cifuentes was working with the U.S. government in 2016 when he first mentioned the bribery allegation to prosecutors. He claimed the alleged bribe to Nieto occurred in October 2012.

A spokesman for Nieto called the bribery claim "false and defamatory" when it first came up earlier in the trial, according to The Associated Press.

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During earlier testimony, Cifuentes said another former Mexican president, Felipe Calderon of Mexico, was bribed by the cartel. LIke Nieto, Calderon has also denied the bribery charges.

Judge Brian Cogan signaled he wanted to limit what was being said in court about the alleged bribes, saying there was a "mountain" of information but "no evidence" to prove the allegations. Defense attorney Jeffrey Lichtman said prosecutors could "be desperate to protect the Mexican government."

Fox News’ Marta Dhanis and The Associated Press contributed to this report.