But tonight, they proved he is already part of the family, after Ms Markle supported her boyfriend at the Invictus Games closing ceremony with her mother by her side.
The singer looked fantastic in a glistening, long-sleeve bejeweled black top studded with pearls.
The Invictus Games are an global sports competition for wounded and sick military personnel founded in 2014 by Harry, younger brother of William, the second in line to the British throne.
Eighteen-year-old Hayley Stover made many girls jealous by getting the seat next to Prince Harry at the Invictus Games in Toronto.
The 2017 games were the largest so far, with 550 participants from 17 nations, including 24 from the New Zealand Defence Force competing in 12 adaptive sporting events.
This is the first time Harry has been pictured with Markle's mother, who is a yoga instructor and social worker and lives in LA. Harry gave a smiling Markle a kiss on the cheek at one point, though they were largely at the back of the darkened box.
"And you never know, this may just be the missing piece of the puzzle to help you regain that satisfaction of serving others once again", he added.
This was the third edition of the Invictus Games, which are to be held in Sydney, Australia, next year.
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Bush and Barack Obama and almost cropped himself out of the photo. "I just love every opportunity to be a part of these events". Saturday will see four foursomes matches and four four-ball clashes as the International Team look to begin their comeback.