Kristen Bell reveals her and Dax Shepard's daughters 'sleep on the floor' in their parents' bedroom

• Dax Shepard and Kristen Bell's daughters sleep on the floor in their bedroom, Bell revealed.
• Lincoln is eight years old, while their younger daughter, Delta, is seven.

Dax Shepard and Kristen Bell's daughters Delta, 7, and Lincoln, 8, sleep in their parents' room, Bell revealed on Shepard's podcast "Armchair Expert" on Monday.

"You know the girls sleep on the floor of our bedroom," Bell casually mentioned before launching into a very smelly anecdote.

She said she had been noticing "a really raunchy smell" in the room and asked all three of her family members if they had farted and all of them had confessed.

"I go, 'OK, my family has gas, big D,'" Bell continued. "I wake up in the morning and I go, 'Wow, nobody's gas has dissipated, but it also smells like it's burning.'"

She said Delta began to notice the smell, too, but Shepard and Lincoln "can't be bothered."

"So Delta and I are, well, being gaslit," she joked, before explaining how she went on a quest to find the source of the smell. There was no pet poop to be found, so Bell went to her husband's side of the bed to investigate.

"I lean down and smell the mattress, Dax's corner, his feet at the corner of the mattress, and I almost hit the deck," she said. "I almost passed out it was so strong."

The culprit of the smell was the couple's OOLER mattress pad, which Shepard had accidentally filled with a protein shake instead of water while in a sleepy stupor.

Bell and Shepard, who don't share Lincoln or Delta's faces on social media for their kids' privacy, have sparked debate after sharing other parenting choices in the past.

While defending their friends Mila Kunis and Ashton Kutcher, who said on "Armchair Expert" that they wait until they see dirt to wash their kids, Bell explained that she similarly waits for "the stink" before bathing her kids.

"Once you catch a whiff, that's biology's way of letting you know you need to clean it up. There's a red flag," Bell said on "The View."