CHRISTIE BRINKLEY is recreating her famous swimming pool scene with CHEVY CHASE in National Lampoon's 'Vacation' for DirecTV, and ET has your first look!

"When this robe comes off, there's nothing underneath it," she teases.

Despite how it may have looked then -- and now -- Christie was never actually nude in the film, though the producers hoped she would be!

"It was about three in the morning and we got out to the pool, and suddenly somebody decided they wanted me to strip and jump into the pool," she says. "There was a little debate there but I just kept saying, 'I don't think so.'"

Ultimately, the scene left it to the imagination.

"And I think it was so much more effective when I just tossed my bra and it hit Chevy in the face," she relates. "It said it all."

Believe it or not, Christie shot this classic scene over twenty years ago. As you can see, it's like she hasn't aged a day!

"Oh, please!" she laughs, saying they had to "pile on" the makeup. All that, and modesty, too!