Brody Jenner and Kaitlynn Carter's split didn't surprise their 'The Hills: New Beginnings' co-stars.

Friends of the pair - who recently announced their break-up, one year after tying the knot in Indonesia - say their union was ''rocky'' and it was inevitable that the relationship wouldn't last.

Jason Wahler told Access Hollywood: ''It was rocky for sure.''

His wife Ashley added: ''I hate to say definitely, because I respect everybody's relationship.

''But I will say, there were a lot of things that people did not get to see, that happened on camera, that they didn't necessarily show.

''I think everybody in the cast kind of knew that it was not gonna work out.''

Meanwhile, Brody, 35 - who is now dating 22-year-old Victoria's Secret model Josie Canseco - recently called for people to stop directing ''negativity'' at his ''best friend'' and estranged wife Kaitlynn, 30, after she was spotted kissing Miley Cyrus.

He shared on social media: ''There is far too much negativity being directed at someone who I love and care about very much. I feel the need to set the story straight. Kaitlynn and I have been best friends for 6 years, and we continue to be. We, like many others before us and many after us, grew in different directions over those same 6 years.

''Kaitlynn is a wonderful person, beautiful and fun to be with, always a positive force in my life. We decided the best move for both of us was to keep our love for watch other strong but move forward separately with our lives. I respect Kaitlynn and care deeply about her. She deserves to be able to move forward with her life with respect and happiness. (sic)''