Chris Brown reportedly "went straight to Rihanna's cabin" when he visited her yacht at four o'clock in the morning.
The 24-year-old singer is currently enjoying a vacation in the South of France with her friends.
Chris, who was convicted of assaulting Rihanna three years ago, flew in to Nice by private jet and then took a helicopter to Saint Tropez to film a music video with rapper Swizz Beatz and Ludacris.
He has chartered a multi-million boat for a week that is docked right next to Rihanna's.
The pair have reportedly been spending the past two nights together.
"Chris took a car at 4am to Port de Golfe Juan, then a tender to Rihanna's yacht and went straight to her cabin - re-emerging at 8am," a source told British newspaper The Sun.
Chris is currently in a relationship with model Karrueche Tran, who has just flown into Cannes to meet him.
Karreuche is aggravated by her beau's insistence on spending time with Rihanna.
"Chris Brown's reason for being there is to shoot a video with Swizz Beatz and Ludacris. But it just so happens Rihanna is there too, which Karrueche wasn't happy about so she went along," the insider explained.
"There's no way she was missing the trip for him and Rihanna to meet up alone."
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