Giovanna Fletcher is used to sharing much of her life online, but discussing her birth plan with our future king was a "surreal" moment she hadn't expected.
Speaking to HELLO! for the launch of her latest novel, Some Kind of Wonderful, the author revealed how the conversation had come about.
"We were at the Prince's Trust," she said, "it was their birthday and they'd invited loads of their ambassadors along." Gi explained that the group - which included herself and husband Tom Fletcher as ambassadors of the charity - had been invited to meet with Prince Charles at Clarence House before the celebrations started.
WATCH IN FULL: Giovanna Fletcher, Lindsey Kelk and Paige Toon join HELLO! Book Club live.
Jump to 4 minutes 20 for the start of the chat.
It was then that the future monarch remarked upon her baby bump (she's currently expecting her third child).
"It was very much [from Prince Charles] 'how long have you got to go?'," Gi recalled. "Then he said something along the lines of 'nowadays, there's all this breathing that people do...' and I was like 'yeah, hypnobirthing, I actually do hypnobirthing'...
So I ended up talking in quite great depth about hypnobirthing and how amazing I found birth. It was really quite surreal," she said.
Giovanna and Tom's third child - due in September - will be a little brother or sister for their two boys, Buzz and Buddy. In June, Tom told HELLO! that he and Giovanna had decided not to learn the baby’s gender, and were still undecided about whether he or she would also have a name beginning with ‘B’.