Heidi Klum flashes Ellen DeGeneres, studio audience

Good thing Ellen DeGeneres provides her guests with free underwear.

Guest Heidi Klum appeared on "Ellen" Thursday wearing a little black dress that was too short to sit down in.

"Did you test that dress out before you came out?" DeGeneres asked as Klum sat for her interview.

"It's short, but I put your underwear under it," Klum admitted, before hiking the dress up to her belly button to reveal a pair of Ellen branded boxer shorts she had plucked from the show's guest goodie bag.

"That's the kind of underwear I suggest you wear under a dress like that," DeGeneres laughed as the audience applauded.