On both occasions his wife, Marina, kicked her philandering husband out of the family home before relenting and letting him come back.
It seems the electorate has a similarly forgiving attitude to Britain's most colourful politician, who has made little effort to disguise his ambition to lead the Conservative Party.
Only 15 per cent of voters said they would be less likely to vote for him because he secretly fathered a child outside his marriage. More than three-quarters (76 per cent) disagreed, saying it would make no difference to their likelihood of voting for him.
No significant variation was apparent across party lines, with 18 per cent of Tories and 17 per cent of Labour and Liberal Democrat voters taking a dim view of Johnson's activities.
If anything, the politician's reckless private life, which also includes a reported affair with the journalist Anna Fazackerley, appears to play into the "cult of Boris". This has led Tories gloomy with the party's fortunes under David Cameron to dream that he will ride in to save them from electoral oblivion - even though he is not an MP.
Paul Goodman, the editor of the ConservativeHome website, said: "In modern politics unconventional politicians are judged by different rules from conventional ones. Boris is part of a small band of unconventional politicians who include Nigel Farage, John Prescott and Ann Widdecombe."
Last week, the Appeal Court said that Johnson's "recklessness" about pregnancy and the feelings of others while engaged in "extramarital adulterous liaisons" raised questions about his fitness for public office.
The court rejected Macintyre's claim that the birth of their daughter, Stephanie, must remain secret.
Yesterday Johnson was tackled over a claim by Andy Coulson, Cameron's former press chief, that he was secretly waiting for the Prime Minister to "fail miserably".
Johnson responded: "I'm always grateful to Andy Coulson for his impeccable career advice but I'm backing David Cameron, who I am absolutely, increasingly, confident is going to win."