“Lost” star Evangeline Lilly said she was once “cornered” into doing a partially nude scene on the popular ABC drama — and that the experience was so traumatizing, it left her in tears.

Lilly, who played Kate on the critically acclaimed, filmed-in-Hawaii series, said the first time she was all but forced to act naked against her will was in Season 3.

“I had a bad experience on set with being basically cornered into doing a scene partially naked and I felt I had no choice in the matter,” she told the Lost Boys podcast. “And I was mortified and I was trembling and I was, when it finished, I was crying my eyes out.”

The actress, 38, did not specify to which episode she was referring, but she appears topless in the Season 3 episode “I Do” as she cuddles with Sawyer (Josh Holloway) after the two have sex for the first time in a cage.

But that wasn’t all — Lilly said when a Season 4 episode called for Kate to undress again, she tried to fight it, to no avail.

“In Season 4 another scene came up where Kate was undressing and I fought very hard to have that scene be under my control. And I failed to control it again,” she said. “And so I then said, ‘That’s it. No more. You can write whatever you want, I won’t do it. I will never take my clothes off on this show again.’ And I didn’t.”

ABC did not immediately respond to a request for comment.

Lilly said she now passes on any script that involves nudity because she doesn’t feel she can be “comfortable and safe.”

Though Kate was one of the most popular characters on “Lost,” Lilly admitted she didn’t always have a fan in her portrayer — and that Kate sometimes “irritated the s — t” out of her.

The actress expressed frustration with how the “Lost” writers wrote the character of Kate, namely the fact she was constantly caught up in a love triangle with Sawyer and Jack (Matthew Fox).

“I always thought she was obnoxious. Not at the beginning, at the beginning she was kind of cool. And then as the show went on, I felt like she became more and more predictable and obnoxious. Because I felt that my character went from being autonomous, really having her own story and her own journey and her own agendas to chasing two men around the island,” she said.

“And that irritated the s — t out of me. And I did throw scripts across rooms when I would read them because I would get very frustrated by the diminishing amount of autonomy she had and the diminishing amount of her own story that there was to play.”

Still, Lilly admitted that while she wanted Kate to “be better” as an icon of strength for women, she did see the benefit in putting a flawed character on screen as a heroine.

“If you don’t have flaws in the women on screen then what you’re telling the world is that women have to be perfect,” she said.

The Canadian actress has previously hinted that she struggled during the show’s filming, admitting to People in July that she went through a “pretty dark time” coming to terms with the superstardom thrust upon her by the popularity of “Lost.”