The legendary CHANEL designer caused controversy last week when he said the party planner - the younger sister of Britain's Duchess Catherine - should ''hide her face'' but friends of the brunette beauty have advised her to retain a dignified silence.
A source told Closer magazine: ''Pippa's devastated by Karl's cruel comments - she's always been confident about her looks. But she doesn't want to retaliate and start a War Of Words. Her friends have tried to make her laugh about it as Karl is hardly a supermodel himself.''
Karl famously hit out at Pippa - who wowed onlookers with her pert posterior at her sister's wedding to Prince William in April 2011 - saying he did not think of her as a beauty like Catherine, who was known as Kate Middleton before she married.
He said: ''Kate Middleton has a nice silhouette and she is the right girl for that boy. I like that kind of woman, I like romantic beauties.
''On the other hand, her sister struggles. I don't like the sister's face. She should only show her back.''