Prince Harry faced a backlash on both sides of the Atlantic earlier this year when he became caught up in the US election.
British royals are not supposed to espouse political points of view, but it was clear to some he was barracking for Joe Biden when he told Americans to "reject hate" and vote in the presidential election.
Now, it appears there is more to the relationship between Harry and the next first family than him simply backing their political views.
Images over the years show he has become particularly close with Dr Jill Biden - America's next First Lady.
President-elect Biden has even joked that his wife had "spent too much damn time" with Harry after the paparazzi caught them hanging out.
The pair are said to have struck up a friendship during Harry's tour of the US in 2013.
During the trip, Harry went to a reception for British and American wounded soldiers in Washington, when Biden was serving as Barack Obama's Vice President.
Harry then went to the Warrior Games in Colorado during the visit, which became his inspiration for the Invictus Games, his sporting event for wounded veterans.
It was there that Harry and Jill are said to have bonded over their shared military links.
Harry spent 10 years serving in the British Army, while Jill's late stepson Beau was a major in the US military.
The pair clearly made an impression on each other, because they were pictured together in London the following year.
Jill was in the UK to support the US team at the first Invictus Games in 2014, and the Bidens and Obamas continued supporting the event.
Two years later, pictures show Harry sitting next to the Bidens as they watched the wheelchair basketball event at the 2016 games in Orlando.
The Bidens then attended the Games in Toronto in 2017 – the same year that Harry stepped out in public with Meghan Markle for the first time.
Although Harry wasn't allowed to vote in the US election, he did break royal protocol for the first time in openly talking about politics alongside Meghan, who did cast a vote.
The Sussexes urged people to vote, with Harry saying it was time to "reject hate speech, misinformation and online negativity".
Meghan called the 2020 White House race the "most important of our lifetime".
The messages were seen as an attack on Donald Trump - who interpreted them the same way.
Shortly after Harry and Meghan's video message, he hit back at one of his press conferences.
"I'm not a fan of hers [Meghan]. I would say this – and she has probably heard that – I wish a lot of luck to Harry because he's going to need it," Trump said.
Harry's comments also angered the British tabloid press.
Morning TV host Piers Morgan said: "Prince Harry poking his woke nose into the US election and effectively telling Americans to vote against President Trump is completely unacceptable behaviour for a member of the Royal Family."
Since the election, both Harry and Meghan have refrained from speaking out about politics – however a source revealed to the New York Post last week that the Duchess of Sussex had cast her vote early via mail-in ballot.
A spokesman for Prince Harry "declined to comment on the current status of Harry's relationship with Biden" when asked by Insider.