Ever wonder what high-level national leaders talk about in private?

According to a forthcoming book obtained by ABC News, French first lady Carla Bruni-Sarkozy once told U.S. counterpart Michelle Obama a story that lends a whole new meaning to the term 'international relations.'

Bruni-Sarkozy said she and French President Nicolas Sarkozy once kept an unnamed head of state waiting while they had sex, the book says.

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

Alter's book -- The Promise: President Obama, Year One -- is to be released next week.

(Posted by David Jackson)