Pippa Middleton not dating ex-boyfriend

London: Pippa Middleton, Duchess Catherine`s younger sister, is not dating ex-boyfriend George Percy, heir to the Duke of Northumberland, says a source.

Middleton and Percy dated in their final year at the Edinburgh University in 2008.

"They have always just been friends. I don`t know how this particular rumour got so out of control. Both of them say they are friends and I`ve not heard or seen anything to suggest otherwise. I couldn`t imagine them together. Their friendship is more like brother and sister," femalefirst.co.uk quoted the source as saying.