Speaking on Channel 4 News, Khan spoke for the entire U.K. saying that Britain should not be "rolling out the red carpet to the president of the USA in the circumstances where his policies go against everything we stand for."
Khan went on: "He tweeted terrible things to me. It hurt my feelings; it cut me deep. Now he needs to pay." Khan appeared to be weeping silently as he spoke softly. "He doesn't even know how to say 'Muslim.' He calls us 'Moozlims.' It's racist, I tell you."
"How dare Trump say that I told Londoners there was no reason to be alarmed? He quoted me out of context. I meant that with all the police presence, people shouldn't be alarmed at that. It's not fair."
Khan asked if he could have a moment to pull himself together as he walked away, surreptitiously wiping his eyes.
The tweet Khan referred to was President Trump saying: "At least 7 dead and 48 wounded in terror attack and the Mayor of London says there is 'no reason to be alarmed!'"
Initially, Khan shrugged off Trump's initial tweet, with his office saying the mayor "has more important things to do than respond to Donald Trump's ill-informed tweet that deliberately takes out of context his remarks urging Londoners not to be alarmed when they saw more police--including armed officers--on the streets."
But on Monday, Trump couldn't let it go. He took another shot by saying it was a "pathetic excuse" by Khan.
Khan suggested in the Monday interview that he sees his position as one of tough love for an important ally.
"I think one of the things, when you have a special relationship it is no different from when you have got a close mate. You stand with them in times of adversity but you call them out when they are wrong," Khan said. "And there are many things about which Donald Trump is wrong."
And there are many things about which Sadiq Khan is wrong. One of them is that he needs to respect the office of the president and refer to President Trump by his title.