In an appearance on "The Late Show with David Letterman" on Monday, Nov. 19, Jessica Biel revealed that a pre-nuptial spa vacation in Austria went terribly wrong and left her literally sitting in between two "butt naked" men trying to figure out a way to escape.

"It was supposed to be a relaxing, Zen-like kind of place," Biel said. " We're in the spa, in the sauna, and in walked two husky Austrian men," she explained. "OK, I thought, this is a little unusual but we're in Europe..."

She said she did not know what the protocol was so "I just laid there froze in my bikini and my robe and my towel and my slippers."

"And I'm like, 'OK I can handle this.' And they come in and they drop their towels - they are butt naked," she said. "They are completely naked. Older husky men."

Letterman then interjected, "now when you said husky, you mean tubby?" to which Biel replied, followed by laughs from the audience, "You say tubby I say husky. Whatever you want to call it they were naked, OK."

She then continued on her story: "And I'm in middle of them. And I'm like how am i gonna get out of here without being rude. And I look over and I realize, oh my god, yes it is confirmed: there are balls on wood. Not just naked but balls on wood, Dave. That's not OK."

Letterman than asked, "Is that the criteria, to confirm butt naked it has to be balls on wood? What do you do, do you say 'boys hellooo.' "

"Honestly I was so stunned," Biel said. "I just laid there sandwiched in between these" - and Letterman cuts her off there.

Her friend walks in to to sauna and ultimately saves her, but Biel might be scarred for life. The actress wed Justin Timberlake in Italy on Oct. 19. 

Tags: Jessica Biel David Letterman