Prince Harry is reportedly revealing how Prince William and Kate Middleton reacted to his and Meghan Markle’s first pregnancy.

Express UK said the royal-born Prince shared some details about the matter in his new and upcoming memoir, “Spare,” noting that he recalled the moment when they shared the news to the then-Duke and Duchess of Cambridge at Princess Eugenie’s wedding in 2018.

The Duke of Sussex is said to have written in his book that he made the announcement to his older brother at the wedding reception in St. George’s Hall in Windsor. He shares, “We were in a big room, suits of armor on the walls. Strange room, strange moment,” as per the outlet.

Prince Harry reportedly continued that Prince William “smiled” when he told him about his and Meghan Markle’s first pregnancy. He is also said to have noted that his brother commented, “we must tell Kate.”

As for the then-Duchess of Cambridge’s reaction, the Duke of Sussex shares in his memoir that she “gave a big smile and hearty congratulations,” as per the publication. He reportedly added, “They both reacted exactly as I hoped - as I’d wished.”

Meghan Markle and Prince Harry welcomed their first child in May 2019.

The public first knew about their pregnancy when Kensington Palace made an official announcement in October 2018.

In “Spare,” the Duke of Sussex also recalls the moment when he first learned about the milestone with the Duchess of Sussex, according to Us Weekly. He is said to have revealed that he fell asleep while his wife took a series of at-home pregnancy tests.

The former working royal reportedly continued that the former “Suits” actress had placed the tests on the nightstand when he woke up, adding that the wands were next to the “blue box with my mother’s hair.”

The outlet later noted in the same report, published Thursday, that the blue box is one of the few things he keeps on his nightstand.

Elsewhere in the report from Express UK, published Saturday, it said that Prince Harry also revealed in his book how King Charles III reacted to the pregnancy news, noting that he and Meghan Markle told him on the same day they shared it with Prince William and Kate Middleton.

The outlet quoted the former working royal from the material, reportedly writing, “Just before a drink reception for the bride and groom, we cornered Pa in his study. He was delighted to learn that he was going to be a grandfather for a fourth time; his wide smile warmed me.”

“Spare” will hit shelves on January 10, 2023.