The couple split up last month amid claims that Bush was unhappy with the media attention surrounding Kardashian.
Insiders have now told the New York Post that the pair will not rekindle their romance.
"They're still friends and speak at least twice a week," one source said. "But there is no chance of them getting back together. Kim is constantly travelling and working and doesn't have any free time. They barely saw each other in the end. They grew apart."
Earlier, reports claimed that Bush is now dating video model Dolicia Bryant.