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The list of reasons why controversial couple Juan Pablo Galavis and Nikki Ferrell broke up is a lengthy one.

In the end, though, it basically came down to the lack of effort and a refusal to compromise by the one-time "Bachelor."

The breakup, a source told Us Weekly, "was not mutual."

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"Everything Nikki wanted, he didn't," another source told the magazine. "She wanted to settle down and he didn't."

Aside from that, the couple had apparently been fighting and the rift became more intense after the pair appeared on VH1's "Couples Therapy," where Juan Pablo refused to tell Nikki that he loved her, which was a point of contention from the get-go of their relationship.

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"I don't think he ever said 'I love you' to her," the second source said, adding that Juan Pablo simply "stopped putting any effort into the relationship."

For those who have followed the couple's relationship, the writing has been on the wall for some time -- beginning with the "After the Final Rose" special when the former soccer pro told Nikki "I like you" after she told him she loved him. Later, on an episode of "Couples Therapy," Nikki Ferrell broke down into tears and questioned why she was in a relationship "if they're not giving you 100 percent."

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A source close to Juan Pablo came to his defense, saying it just didn't work out. "They were not seeing eye to eye on anything," the insider said. "Juan wanted Nikki in Miami. Nikki didn't want to leave her family, friends or job. Meanwhile, Juan wouldn't even consider going to Kansas."

"Nikki felt like she was doing all the work in the relationship, and that Juan expected her to join his life," the source said. "She couldn't get him to compromise at all. He didn't put Nikki's priorities first and she had enough."