Warren Buffett is known by many to be a master negotiator and a talented speaker able to make the simplest of remarks enlightening.

But on his 3-hour long interview with CNBC today, he revealed one individual that always made him tongue-tied: the late Princess Diana.

"I was in a room alone one time with Princess Di at a party. Somehow we find ourselves in this library," he said. "In 15 minutes, I had trouble remembering my name, I couldn't figure out anything to say, it was a total disaster."

Buffett said he met Diana a second time at a party hosted by former Washington Post publisher Katherine Graham right before her untimely death.

"She had been to the White House that day and she had said that Bill Clinton was the sexiest man alive," Buffett recalled.

The comment, obviously, didn't do a lot for Buffett's self-esteem. "When Princess Di was looking at me and said that he was the sexist man alive. The fact that she was looking at me did not make me feel like that," Buffett said to laughs all around.

Video of Buffett's remarks below: