Michelle Obama 'shocked' by Bruni's sex talk?

In the first meeting between First Lady Michelle Obama and French First Lady Carla Bruni, Bruni asked Obama if she and President Obama had ever kept visitors waiting while they had sex, according to a new book.

Washington (CNN) - A new book reveals an unusually personal–and apparently awkward–moment during the first encounter between First Lady Michelle Obama and France's First Lady, Carla Bruni.

The book's author, Newsweek editor Jonathan Alter, writes that Bruni, "delighted in telling friends that she shocked Michelle Obama at their first meeting."

Alter describes the meeting between the first ladies in which Bruni boasted that she and French President Nicolas Sarkozy, "once kept another foreign leader waiting while they finished having sex."

"Bruni wanted to know if, like the Sarkozys, Michelle and the president had ever kept anyone waiting that way," Alter writes. "Michelle laughed nervously and said no."

The book, "The Promise: President Obama, Year One," was obtained by CNN in advance of it's May 18 release.