billy crystal princess diana orgasm sceneAlamy

Who can forget the little old lady's quip after Meg Ryan's fake orgasm in "When Harry Met Sally"? "I'll have what she's having" was one hell of a reaction.

In the new issue of People, star Billy Crystal recalls another priceless reaction -- by Princess Diana at the movie's Royal Command opening in London.

"She was laughing so hard, just belching it out," he remembers. "She had the kind of laugh where if you were on a date, you'd never want to see her again."

Considering Princess Di is still considered one of history's most beautiful women, that's really saying something!

After the scene ended, Crystal adds that she "grabbed my hand and said, 'So naughty.'" Diana may have been a princess, but she wasn't a prude! [via People]

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