Kristen Bell Reveals the Clever Answer Dax Shepard Gave to Their Daughter's Question About Sex

Being honest with her kids about where babies come from has led to a few unexpected moments for Kristen Bell.

The actress, joined Stephen Colbert on Thursday night for a virtual chat on The Late Show, where she discussed her new children's book The World Needs More Purple People and recalled a recent moment when her and husband Dax Shepard's older daughter Lincoln, 7, asked a thought-provoking question when her parents "tried to steal away for a hike the other day."

"My sister was here watching the kids. We masked up and we were like, 'Oh, we'll just walk down the street. There's a great hike near our house.' And on our way out the door, my 7-year-old stood in the door and she held it open. She goes, 'Uh, are you going to do a sex?' " said Bell, 40.

While the comment "caught" Bell and Shepard, 45, "by surprise," thankfully the Armchair Expert podcast host's quick thinking got them out of the door unscathed.

"We've talked to her about what sex is, but we've never talked about us doing it. Dax just really quickly said, 'We'd love to, but it's illegal publicly. Bye!' and closed the door," said The Good Place alum.

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

RELATED: Sex, Santa and the Easter Bunny: How Kristen Bell and Dax Shepard Keep It Real with Their Daughters

Bell also told Colbert, 56, that Lincoln and her little sister Delta, 5½, "are very talkative," joking that being around them nowadays is "truly like having two crazy parakeets stapled to your shoulder all afternoon, where they're just talking so much."

And the girls have learned how to keep themselves busy while indoors amid the COVID-19 pandemic's social-distancing practices — with some activities being a little more stressful than others for Bell.

"Lately, they've been making forts but they've been expanding into movie furniture," she shared. "So I will wake up at 8:30 and none of the furniture that was in the room previously will be in the room."

The family is getting their rest in the meantime, though. "We've been sleeping in lately — like, till 8:30, 9 — because they can get up now and I don't have to worry about them turning the oven on; they know not to," Bell said.

RELATED VIDEO: Kristen Bell: Homeschooling Kids with Dax Shepard "Made Me Fall Much Deeper in Love with Him"

Bell has been candid in the past about how she plays it straight with her girls when it comes to some of the more difficult topics to talk with children about, including sex.

"They've asked about sex before and Dax says, 'Well, there's a penis, there's a vagina and there's an ovum and there's ejaculate,' " the Frozen 2 voice actress said in September 2018 on the WTF with Marc Maron podcast. "And they're like, 'Can I have some juice?!' They're just off of it. They don't care."

She added about inevitably having the conversation again with Delta and Lincoln in the future, "That's fine. Sex is wonderful. I want my kids to have sex. I want them to have good, healthy, positive, happy, wild sex."

The previous November, Bell revealed during an appearance on The Talk that her kids have "walked in on" her and Shepard "having sex," adding quickly after the show's co-hosts gasped, "That's how they were made, it's okay!"