By Anushka Asthana, Political Correspondent
Boris Johnson has been forced to admit he doesn't know which two London teams will play in a cup final this weekend – and took to Latin to defend the PM, during a grilling by school children.
Robert Ebner-Statt, 9, had to tell Boris Johnson that it was two of his city's teams - Chelsea and Tottenham Hotspur - playing in tomorrow's Capital One league cup final at Wembley.
That was despite the Conservative politician's claim that "I support all London clubs, I levitate".
He added that for "some reason I cannot fathom, my sons support Newcastle Utd".
Mr Johnson came unstuck over football during a grilling by children as part of Hotseat - a collaboration between Sky News and the national newspaper for young people, First News.
During the session he answered questions about terrorism, education policy, obesity, his political ambitions and much more.
At one point, Mr Johnson revealed that he gave lorry drivers "a piece of his mind" if they sounded their horn at him while cycling, because it made him "see red".
While previous Hotseat guests, Chancellor George Osborne and Education Secretary Nicky Morgan, refused to answer basic timetables questions, Mr Johnson was asked about a different subject - Latin.
Sophia Hindmarsh, 10, tried to play on rumours that Mr Johnson would like to become Prime Minister, by asking him to translate "Princeps Esse Velim" (I want to be leader).
Smiling, Mr Johnson quickly replied, "I know what you are trying to get me to say," and instead hit back with "Volo David Cameronem esse principem" - which he said meant "I want David Cameron to be Prime Minister."
It was not his only defence of the Conservative leader.
When asked if he wanted to be Prime Minister, he said: "I think Dave is going to get back in. I think it is more likely, frankly, that one of you will take over in some distant future than I will."
He described Mr Cameron as "very, very competent" and an "expert leader of the country".
The Mayor also spoke on a range of other issues, including:
Immigration and second jobs...
He defended immigration, as long as people were not "skiving, idling, loafing, leeching", and he entered into the debate about MPs' salaries and second jobs.
Mr Johnson claimed politicians should certainly not "be going around trying to take more dosh off the taxpayer".
Ministers, he added, should not be doing private consultancy work on the side. But he insisted that MPs were not "twerps" - well "not all twerps".
Jihadis and tuition fees...
Mr Johnson told the children that the thing he most wanted to change in the world was children being lured into what he called "Jihadi nonsense".
And he criticised Labour's policy to cut tuition fees, arguing that it was right for graduates who "earn massively more than people who don't go to university" to pay for their education.
Parenting, regrets and weird gifts...
The young people asked Mr Johnson what sort of dad he was - "embarrassing"; his biggest personal and political regrets - "my failure to get anywhere as a rockstar"; his weirdest gift - "a banquet of camel"; and his celebrity crushes - to which he strangely responded "Basil Brush".
Bouts of road rage...
On road rage, he said: "When lorry drivers come up behind me and I'm cycling innocently, keeping to my side of the road and they decide because they are so big and their lorry is so powerful and they just want to clear me out of the road and they hoot aggressively then I do see red a bit. I do."
He admitted entering into altercations if he pulled up beside a lorry driver who had done that at the traffic lights.
The embarrassing zip wire...
He also talked about the famous incident when he got stuck on a zip-wire, describing his "embarrassment and personal discomfiture".
He said he was accompanied by a bodyguard called Carl, who used to work for Tony Blair.
When he asked him for help, he said Carl simply took out a mobile phone and "took a photograph of my rear end".
The Boris Factor...
The young people also asked what the "Boris factor" was, to which he replied it was doing your best and turning up.
"My strong advice to you, turning up is about 90% of success in life," he said.
Healthy-ish eating…
On obesity, he said it was right to encourage children to eat healthily by limiting their options.
He tried to compare an unhealthy option like pizza and chips to a healthy option - but took some time to think of one, finally landing on ratatouille and salad.
Asked which he would choose, he said: "I would probably have both".
