When Meghan Markle first met Her late Majesty the King in October 2016, she had no idea that she was scheduled to be introduced to the Queen that day. She was dressed in jeans and a black sweater for a casual Sunday lunch in Windsor and had no plans to meet the Queen. But when the Queen unexpectedly stopped by the Royal Lodge to join them for lunch, Princess Meghan had no time to prepare, Prince Harry writes in his upcoming memoir, Spare.

Harry writes that the couple was on their way to lunch when they "received word" that the Queen had stopped at the Royal Lodge, home of Prince Andrew and his ex-wife Sarah Ferguson, on her way back to the castle from church. Meghan, who was scheduled to meet Ferguson for the first time that day, was initially excited to meet Harry's grandmother and said, "It's fun! I love my grandmother." Harry quickly informed his girlfriend that this was no ordinary "meet the family" moment: "You're meeting the Queen," Harry told her, and asked if she knew how to bow. When Meghan "shook her head," Ferguson gave a brief tutorial shortly after they arrived at the Royal Lodge.

When they entered the house, Harry saw that "Grandma" was wearing a "brightly colored dress and matching hat." He wrote, "I could see Meg regretting her jeans and black sweater." 'I too regretted my own shabby trousers. We didn't make a plan. I wanted to tell Grandma, but I was busy with Princess Meghan's visit."

As Us Weekly reports, the meeting went well, despite the fashion faux pas. Harry told "Spare" that "after 20 minutes, the grandmother told me she had to go ...... She made eye contact with Meg, waved, and smiled warmly," he wrote.

But when Meghan met Harry's father, then Prince Charles, she was more than ready. Apparently, the current king does not approve of women who wear too much makeup, and Harry instructed Meghan to wear more makeup when they first met at Clarence House, Prince Charles' residence.

"Meg looked beautiful," Harry wrote, adding that for this introduction, Meghan wore a "full skirt with a floral pattern."

Harry also told his then-girlfriend how to put her hair up, saying, "Pa (Charles) likes it when women let their hair down." He added that it was also the Queen's preference and that she often commented on "Kate's beautiful mane."

For this audience, Harry also had time to prepare an appropriate greeting protocol for Meghan, "Us Weekly" reported.

"Meg and I rehearsed this moment many times," he wrote. "Bow to Pa. 'Your Highness' or 'Sir.'"

He told Princess Meghan to kiss Prince Charles "if he leans in" and shake his hand "if he doesn't." To Prince Charles' wife, then the Duchess of Cornwall, now Queen Camilla, Harry told Meghan that a bow was not necessary. 'Are you sure?'

"I didn't think it was appropriate," Harry wrote.

Harry and Meghan spent a pleasant evening with Charles and Camilla, and the conversation turned to their shared love of dogs. [Meg spoke of their two "fur babies," Bogart and Guy.