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"Matt's sick of always following after her like a puppy dog all over the world," the source told the magazine. "He wants something more normal."
Kemp, an outfielder for the Los Angeles Dodgers, began dating the 22-year-old after her disastrous and very public relationship with Chris Brown, that ended with his infamous assault on her in 2008. In comparison, Rihanna called her relationship with Kemp "so easy" and "my peace."
Apparently, the breakup wasn't so difficult either. "It was never as serious as it looked," the source added. "It was always just [about] having fun." Plus, Rihanna "basically was just over it."
Watch Rihanna's 'Only Girl (in the World)'