The chart-topping Talk That Talk star, who is taking a break after her "exhausting" 777 tour to promote her seventh album Unapologetic, put up the photo of her giving her ex a bear hug on Instagram.
"i dont wanna leave!!! Killed it tonight baby!!!" she wrote alongside the image.
"Don't believe me just watch #newtoy#justcusimnumber1 #roleylife #dopedealer," she wrote.
Rihanna recently insisted she was still single, but the rumour mill went into overdrive when she tweeted a picture of Chris in bed a few days ago.
The snap appeared to show the shirtless singer sprawled face down on a bed on a Simpsons Duvet, with other paraphernalia from the animated series visible, and was headed "Bart Obsessed".
The couple split in 2009 after he admitted assaulting her.