‘He’s fine. They’re fine. They’re two really good people. I know him very well, and I don’t know what that was all about,’ Trump said, choosing his words carefully.

‘But I know him very well, and they’re fine.’

That prompted an interjection from Musk. ‘I know a little shiner here,’ said the world’s richest man, whose black eye was visible throughout the event Friday.

Musk only later revealed the source of his injury. ‘I was just horsing around with Little X,’ Musk explained to the cameras and reporters. ‘I said go ahead, punch me in the face.’