The 'Behind Closed Doors' singer insists Katie's recent erratic behaviour shows why he will never take her back, and labelled rumours they will reunite at Christmas "offensive".
A source close to the singer – who raises three children with Katie, Harvey, Seven, Junior, four and Princess Tiaamii – told Britain's Daily Star newspaper: "There is no way Pete would ever get back with Katie.
"He is shocked to the core that rumours are circulating that they get back together. If people knew the whole story and everything that has happened over the past year they'd understand why it's very offensive for people to even ask him if they're going to get back together."
Peter, 36, has remained tight-lipped on why he decided to dump 31-year-old Katie in May and insists he will never reveal the real reason because he doesn't want his children to grow up with such "sordid details" in the public domain.
The 'Behind Closed Doors' singer is now looking forward to Christmas with his family.
He said: "I'm looking forward to 2010, new challenges and adventures. I've bought three different Christmas trees and have chosen a different theme in each room."