According to the book, titled 'The Promise', penned by American journalist Jonathan Alter, 55-year-old Sarkozy is usually too busy to fulfil his 42-year-old wife's "physical needs", the 'Daily Express' reported.
"The press of state business prevents her husband from making love to her as much as she would like," the author wrote in his book.
But the book has also claimed that the former Italian supermodel-turned-singer told the US First Lady Michelle Obama that she kept a "senior Head of State" waiting while she was making love with President Sarkozy.
Although Bruni didn't identify the "senior Head of State", speculation mounted in France that it was none other than the 84-year-old British monarch who was kept waiting during the French First Couple's official trip to Britain shortly after her marriage two years ago.
The Sarkozys spent a night at Windsor Castle during an official trip shortly after their marriage two years ago.
In fact, Bruni, whose past lovers include Mick Jagger and Eric Clapton, shared her sexlife secrets with the US President Barack Obama's wife at a meeting in America, the book has claimed.
