The pair had a turbulent relationship when they appeared on reality show 'The Hills' together and although they briefly reconciled, they now don't have any contact.
Lauren told Us Weekly magazine: ''I don't talk to Kristin anymore.''
And it seems Kristin - who welcomed son, Camden, into the world last month - is not the only 'Hills' cast member Lauren doesn't speak to.
Audrina Patridge also revealed her relationship with Lauren ended as soon as the reality TV show finished.
She said: ''I don't really talk to Lauren or see her at all. I think there was a little bit of a falling out. We kind of went our separate ways. The show brought us together and without that show, we all kind of go back to our own thing.''
However, she did say there could be a 'Hills' reunion show in the not-too-distant future.
She said: ''Give it another year or two years, because then everyone will be established. I feel like between two years ago and now, everyone is transitioning and figuring it out.''