Tim Gunn Recalls Heidi Klum Preparing the Iconic Worm Costume (Exclusive)

Tim Gunn remembers being in the room while his girlfriend Heidi Klum prepared one of her most famous Halloween costumes of all time.

Speaking to PEOPLE at Rooftop Happy Hour: Halloween Edition with Tim Gunn, an annual event and Halloween costume parade at the New York Public Library, on October 25, Gunn opened up about what it was like being with his ex Project career co-host as she “prepared” for her Halloween parties, including in 2022, when she famously returned to the event dressed as a worm after the pandemic.

“It got to the point where no one other than her makeup people knew what she was actually going to do,” Gunn tells PEOPLE. “And I couldn’t say it. Just that it was really weird.”

Klum's costume included a curved head, a long tail, and realistic ridges that covered her entire body, except for her eyes and mouth. Klum's husband Tom Kaulitz accompanied her dressed as a fisherman.

“The year she was the worm was the first time I actually interacted with her hair and makeup people because they were making these prosthetics,” Gunn says. “And they said, 'We told her we can't do that.' “That’s completely too ambitious.” But they did it.”

In addition to Project careerGunn and Klum are also contributors to the Prime Video reality show Make the cut. The model has worn elaborate Halloween costumes over the years, including Jessica Rabbit, a werewolf and an old lady.

Gunn also noted how “uncomfortable” the worm costume must have been, recalling Klum walking the red carpet at her party that year.

“She kind of fights her way through,” Gunn says. “I mean, I said to her afterwards, 'If you had fallen over, you would never have been able to get up again.' And she said, 'I actually fell over and had a lot of help getting up.'”

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Gunn also says that despite many notable Halloween getups, Klum doesn't have a personal favorite.

“I love all of Heidi’s costumes. I don't want to sound like I'm just being politically correct. They’re always so different,” Gunn says.

“I have no idea what she’s doing this year,” he adds. “She loves Halloween. And she usually makes plans for next year the day after Halloween.”

Gunn, along with librarians from the New York Public Library, served as judges during the NYPL costume parade. The annual event invites New Yorkers to dress in literary costumes inspired by their favorite books, poems, characters and authors. Gunn has served as a judge since 2017.

Gunn, who is also the author of books like Gunn's golden rules (2010), Tim Gunn's fashion bible (2012) andTim Gunn: The Natty Professor (2015) says that although he doesn't dress up for Halloween himself, there is a bookish costume that he would wear if he attended the parade.

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“I would probably go as Edgar Allen Poe,” Gunn says, adding, “I think he’s inextricably linked to Halloween in a lot of ways.”