*Following rumors of the two spending more and more time apart, UsMagazine.com is quoting a source who claims Rihanna and Matt Kemp have called it quits for good.

“It happened over the last few weeks,” explains the source. “She basically was just over it.”

Los Angeles Dodgers outfielder Kemp, 26, helped Rihanna, 22, move on from Chris Brown, who infamously assaulted her in February 2009. The duo were first spotted frolicking together in Cabo San Lucas last January, and slowly opened up about their romance in the spring.

A rep for Rihanna (she’s currently vacationing with family in her native Barbados) has yet to comment, but the insider tells Us Weekly the singer has been “so busy.  He just can’t keep up with her crazy travel schedule.”

“Matt’s sick of always following after her like a puppy dog all over the world. He wants something more normal,” the source adds.

Plus, the insider says, “It was never as serious as it looked. It was always just [about] having fun.”