The actress said she “couldn’t tell anyone I was pregnant because I didn’t want them to know.”

No one could’ve expected the secret that Julianne Moore was keeping while filming The Big Lebowski.

During a visit to The Drew Barrymore Show on Wednesday, the actress explained that she chose to keep her first pregnancy a secret while shooting the 1998 cult classic and, as a result, recalled being “so nauseous” while filming its legendary dream bowling scene.

“Can I tell you? I was pregnant with my son. The first time I was pregnant. I was so sick that day,” Moore said about the scene. “I was so nauseous I could barely move, and that dress was really solid and made from Styrofoam, and I was always like, ‘Oh,’ every time I moved… I was just unbelievably sick and I couldn’t tell anyone I was pregnant because I didn’t want them to know.”

Julianne Moore in ‘The Big Lebowski’.

Gramercy Pictures/courtesy Everett

In the sequence, The Dude (Jeff Bridges) dreams up a sexual bowling-filled fantasy involving him and Moore’s character, Maude Lebowski. Set to the tune of Kenny Rogers’ “Just Dropped In (To See What Condition My Condition Was In),” the pair dance and practice throwing a bowling ball in unison together before a man with a large pair of scissors pulls The Dude from his striking reverie.

While visiting the show, Moore also revealed the technique that she used in order to get through scenes with Bridges without breaking. “Jeff is such an extraordinary person. He’s so funny, so generous. I couldn’t look him in the eye without laughing,” Moore admitted. “I’d have to look at his mouth while he was acting because if I saw his eyes, I’d start to laugh. Or I’d look just beyond him or something.”

Host Drew Barrymore praised Moore’s unique technique, before turning back toward the image of Moore and Bridges on the screen behind them.

“That is the last outfit you want to be in pregnant and nauseous,” she commented. Moore wholeheartedly agreed, adding, “Just awful.”

Drew Barrymore and Julianne Moore on ‘The Drew Barrymore Show’.The Drew Barrymore Show/Ash Bean

Moore welcomed her first child, Caleb, with her husband Bart Freundlich in 1997. The couple also share a daughter, Liv, born in 2002.

Written, directed, and produced by the Coen Brothers, The Big Lebowski follows laid-back dude Jeffrey Lebowski as he gets swept up in a case of mistaken identity after being confused for a millionaire with the same name. The bowling aficionado then embarks on a dangerous quest with his bowling pals that sees him tussle with thugs, meet the real Big Lebowski, hide ransom money in his car, and most importantly, bowl.

Watch Moore discuss being pregnant on the set of the film in the clip above.