Image copyright
Getty Images
The BBC's Tara McKelvey is travelling with Trump as he visits the UK.
Along the way she'll report on his efforts to promote the "America First" doctrine and follow protocol at Windsor Castle when he meets the Queen.
It was all smiles and hand-holding at a swish dinner in the countryside on Thursday night but hours later, the US president has thrown a hand grenade into the carefully choreographed welcome.
13 July - Testing times
Prime Minister May waited for President Trump at Chequers, a 16th-century mansion outside London.
After he got out of his vehicle, he mouthed the words "How are you?"
They acted in a friendly manner, and he followed her inside. As they walked, he put his hand towards the small of her back, protectively, but he didn't touch her.
Inside they sat in an ornately-decorated room and spoke to journalists. It was an awkward meeting.
Trump was deeply critical of May in The Sun, and he's here for a visit that was supposed to showcase the special relationship. She and other world leaders have steadfastly hung on to the idea that old alliances remain steady - despite what the president says.
He tried to reinforce that idea: "The relationship is very, very strong," he said while sitting next to her.
Still he's testing the limits.
Whether he can truly smooth things over with the prime minister - in private as well as in public - and give the two leaders a chance to get beyond the latest row remains to be seen.
12 July - Smiles on British tarmac
President Trump knows how to make an exit - and an entrance.
"Will Brussels ever be the same?" one of my colleagues wonders aloud as we fly over the city on Air Force One, heading for the UK.
Trump threatened to leave Nato if his allies didn't increase their defence spending, and he claims credit for the way they have responded.
Behind the scenes, his aides struggle to explain his position on Nato and seem uncertain about his plans.
At one point someone saw an official rushing down a hallway of the new Nato headquarters with a lectern - and we knew the president would soon be speaking.
But people who work for the president seem exhilarated by the experience and say they're looking forward to his stay in London.
The president says he's popular here - despite the fact hundreds of thousands of people say they'll be protesting on the streets.
He's made a splash on the tarmac in Essex, at least. It's a lovely day at Stansted Airport and people here are smiling and seem happy to see him.
He'll now fly on the presidential helicopter Marine One to Winfield House, the US ambassador's residence. I'll be in a helicopter near him in the presidential fleet - and we'll see how things go.