Jennifer Arcuri says the Prime Minister asked her to cover the cost of his pint when the pair met for a drink.
Boris Johnson is facing a probe over whether he breached rules while he was Mayor after Jennifer Arcuri told of their affair.
In an exclusive interview with the Sunday Mirror, the 35-year-old said they were in a relationship between 2012 and 2016.
Questions first arose in 2019 after it emerged that Arcuri had received public money and access to trade trips led by him.
He now faces a probe over whether he breached a code of conduct while Mayor of London.
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After winning a second term as Mayor, Boris contacted Jennifer and they arranged to meet for a drink at the swish Tavistock Hotel in London’s Bloomsbury.
But the PM arrived looking “dishevelled” and short on cash, which Jennifer said ‘cracked her up.”
She said: “He showed up late, dishevelled and chaotic. He was biking – he came in with his helmet. I thought, ‘That’s a great look for the start of this’.
“He went to the bar and came back within a minute and said, ‘Jennifer can I borrow £3.10’ I thought, ‘I’m a student buying you a beer, you should be ashamed of yourself’.
“It cracked me up. He asked things like where did you come from, what do you want to be I remember being enchanted with this man.”
Boris Johnson faces an inquiry by the Greater London Authority – responsible for the mayor’s office – over claims his failure to declare his relationship with Arcuri may have been a breach of the Nolan Principles of Public Life, which are contained in the Mayor of London’s code of conduct.
Arcuri was granted access to events at three top level trade missions, despite her businesses not meeting the criteria for the trips.
The Independent Office for Police Conduct said there was no evidence he’d committed the criminal offence of misconduct in public office but he may have breached the Nolan Principles.
Len Duvall, the chair of the GLA oversight committee which is conducting the investigation said: “Our investigation will consider whether Boris Johnson conducted himself in a way that’s expected from anyone in that position.
“It’s important we get those answers, because Londoners deserve to have their politicians held accountable.”
Weeks later, Boris told Jennifer that he couldn’t “stop thinking” about her after they met for a meal at Ciao Bella on Lamb’s Conduit Street.
She said: “He gave me a hug in front of everyone. It just felt so natural. We had red wine, I had a Nicoise salad and he had fish and chips and then ate off my plate.
“He was very forthright. He said, ‘I can’t stop thinking about you, I want to date you, I really like you’. I said, ‘I’m not someone you play games with.
“You are always honest with me and you respect me and my time. If you don’t want to see me, you just tell me’.
“He said, ‘I’m not one to fall for American women’. I responded, ‘I’m not one to fall for politicians – we’re going to have to play this very slow’.
“This is where I got to see a little bit of the man for the first time and I’d be lying if I was to say I didn’t love who I was seeing.”
She says Boris begged to go home with her after stroking her leg under the table during the meal.
“He screamed, ‘Kiss me!’ And I said, ‘Mr Mayor, I do not kiss politicians on the street’. He said, ‘This is my city, I don’t care,’ Jennifer added.
No 10 declined to comment.
Read Jennifer Arcuri’s full story in the Sunday Mirror, in shops today.