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This time, she gets the award for worst sidekick.

“Smallville” star Allison Mack gave a Teen Choice Award-worthy performance Monday when she pleaded guilty for her role as the right-hand woman in sex-slave cult Nxivm — sobbing like a soap star the whole time.

A blubbering Mack — who won the dubious honor of “Best Sidekick in a TV Series” for her role on the CW Superman drama in both 2006 and 2007 — appeared in Brooklyn federal court where she copped to racketeering and racketeering conspiracy charges, including extortion and forced labor.

“I’m here to plead guilty before your honor,” the actress said, before crying so much that Judge Nicholas Garaufis stopped to offer her tissues.

“I must take full responsibility for my conduct. I am very sorry for my role in this case. I am very sorry to my family and to the good people I hurt through my misguided adherence to [Nxivm leader] Keith Raniere’s teachings,” Mack continued after composing herself.

Sporting a beige sweater, black pants, leopard-print shoes and a brown straw piercing her bun, the 36-year-old confessed to being part of secret master-slave group within Nxivm called DOS.

Mack had been facing sex trafficking charges — prosecutors allege women in DOS were branded with Raniere’s initials and groomed to have sex with him — but they were not among the counts she pleaded to Monday.

However, she still admitted to keeping a slave and that she instructed women in the group “to perform services for me.”

She said the system was “designed to make them think they could suffer serious harm” if they didn’t perform the services — because they’d handed over damaging collateral to DOS such as nude photos and financial details.

“I was a member of a secret society founded by Keith Raniere,” Mack told the court. “I concealed Keith Raniere’s role as the head of DOS.”

She said she had believed Raniere’s intentions were to “help people” but she was “wrong,” and vowed to be a “better person”

Asked if she had a clear head, Mack admitted she “had one beer last night.” While the beverage didn’t violate the terms of her bail, it does run afoul of the strict Nxivm diet that calls for near zero calories.

Mack is facing 40 years in prison. It was not clear if she has a cooperation deal with the government, and her lawyers declined to comment.

The actress was among six people arrested last year over their roles in Nxivm, including Raniere and Seagram’s liquor heiress Claire Bronfman, who helped fund the cult with her vast fortune.

Her plea comes after Nxivm co-founder Nancy Salzman and daughter Lauren Salzman both pleaded guilty last month to racketeering conspiracy charges for their roles in the group.

It also came right before jury selected was set to begin for the trial.

As Mack exited the courthouse surrounded by a press scrum Monday, she walked right by the throng of potential jurors who could sit in judgement of her co-defendants.

Hundreds of people were instructed to appear in person to fill out questionnaires sharing their views on sexual deviance, abortion, Scientology, cults other related topics.

The potential panelists were also introduced to Raniere, Bronfman, and Nxivm accountant Kathy Russell — but didn’t show any recognition until Garaufis announced Bronfman’s attorney Mark Geragos, who was linked in reports to celebrity lawyer Michael Avenatti’s alleged attempts to shake down Nike for $20 million.

There were also audible groans from the crowd when Garaufis said the trial was expected to last six to eight weeks.

Earlier Monday, a lawyer for Russell asked Garaufis to throw out the indictment against the accountant, saying she wasn’t aware when she testified before the grand jury that she was anything other than a witness.

The judge did not immediately rule on that motion.

Mack is scheduled to be sentenced Sept. 11.