Kristen Bell is opening up about a Frozen joke for adults.

The Nobody Wants This star recently looked back at the 2013 animated classic for Vanity Fair, and revealed that a lyric from the song “For the First Time in Forever” included an intentional double entendre.

“‘Why have a ballroom with no balls?’” she sang while watching the clip, in which Anna celebrates as her castle reopens its doors.

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“How did we get that joke in there? Come on! We slid it under the radar,” she exclaimed.

It almost didn’t make it in,” she continued.

“But then we were like, ‘What are you talking about? That’s not what it means. Don’t be a perv.’”

She went on to explain how she helped create her messy character, whom she wanted to be “lovable but not as put-together.”

“It occurred to me that I would do anything they asked me to, but what I should be valiantly striving for is to create a character that I really needed to see when I was 11 years old, which was someone like this character,” she recalled.

“I said, ‘All the Disney princesses stand like this. Their hands are always perfect, their posture’s perfect. I want her to be the opposite. I want her to wake up with drool in her mouth, and I want her to snore, and I want her to talk too much and too fast and wear her heart on her sleeve and trip over things.”

“Thankfully this whole experience was really collaborative,” she said.

“Some of those things they wrote in, and others they didn’t, and they let me kinda take the reins. Like, the waking-up sequence, she was just waking up normally, and I said, ‘Can I add some snorts? Can you add some drool? Can I make this very realistic and kind of dorky?’ And they were open to all of it, and I still get such a sense of joy when I see it ’cause I’m very proud.”

Find out how her husband reacted to her on-screen chemistry with Adam Brody.

Watch her explain…