“I’m Proud of Being the Curvy Model”

Heidi Klum didn’t plan on walking the runway of the Victoria’s Secret Fashion Show last night, but let’s just say she’s a little bit impulsive. “I felt great the night of the fashion show and decided last minute to walk,” the supermodel, 36, who welcomed daughter Lou, with husband Seal, last month, tells PEOPLE exclusively. Klum, who had already been fitted for her dress, opened the Enchanted Forest-themed part of the show, wearing a vine-strewn corset and a full white skirt. “I loved my outfit,” she says, “so I thought, why not?” Her surprise appearance, known only to Victoria’s Secret insiders, drew screams and applause from a shocked audience during the live show Thursday night. Though Klum, who was expected only to host the festivities, said that while her new job behind the scenes meant there was “definitely less pressure,” walking in the show was a thrill for her. “I’m proud of being the curvy model on the Victoria’s Secret stage,” she says, adding that she enjoyed the show herself. “The Black Eyed Peas and all of the looks for the show were fantastic!” You can watch Heidi — and all the Angels — hit the runway when the Victoria’s Secret Fashion Show airs on CBS at 10pm EST on Dec. 1.