The 21-year-old singer, introduced to Kemp, 25, by friends in November, is currently vacationing with the outfielder at a luxury resort in Cabo San Lucas.
While hanging poolside on Jan. 4, the lovebirds "couldn't keep their hands off of each other," says an eyewitness, adding that once back on their patio the pair "kept kissing while gazing out over the ocean."
"Rihanna wants the world to know that she is happy with Matt," says an insider. So far, things between them are looking good. He certainly kept her "constantly giggling," says an onlooker, when they went shopping at The Grove outdoor mall in L.A. on Dec. 22.
"They've only had a few opportunities to be together, but those times have been fun," says Kemp's agent Dave Stewart.
Adds an insider, "They really like each other."
With reporting by REAGAN ALEXANDER and PERNILLA CEDENHEIM
G Tres / Splash News Online