Although Mary-Kate and Ashley Olsen are fiercely private, details about the twins’ lives are slowly emerging. The latest: how the two achieve their signature smiles.

“Every time they pose and smile, they say the word ‘prune,’” a source close to the girls told OK!.

Another source close to the Olsens could not confirm the precise word they use as their smile trigger, but says their smiles are keys to their identity. “It could be true (that they say prune) but unfortunately I can’t say — they like to keep their personal lives personal,” said the source. “They do care about their smiles though. Mary-Kate has slightly thinner lips and more of a playful grin, while Ashley tends to go for a full-on pout. It has been the obv(ious) way to tell them apart for years.”

Source

WENN