The couple, who started dating in 2007 and broke up briefly in 2009, haven’t ended things – but they are taking a step back in their relationship.
"They are trying to decide what to do right now," a source tells PEOPLE. "Reggie has issues with her busy life and schedule and she can’t give it all up."
But this couple isn't calling it quits yet.
On Monday, Bush flew to Miami and spent the day with Kardashian. Says the source: "It was super cool between them."
After reconciling in Sept. 2009, Kardashian told PEOPLE that her time apart from Bush would ultimately help them grow stronger as a couple. "I think sometimes people need to take a break just to take time off to see how much they need each other and how much they really are compatible," she said at the time. "We just made the decision that we want to make it work, and the time off was really beneficial for the both of us."
Kardashian subsequently bought a house for herself in Beverly Hills, and the couple considered moving in together.
"She's totally happy and fine with everything," the source says. "Kim and Reggie are best friends; they really are. It's just more that he can't deal with her life and all the fame she's gotten. She and Reggie started dating before she even had her show. They are working on seeing what they both want."
Reps for both Bush and Kardashian did not return calls for comment.