Rihanna and Rob Kardashian spent their entire Saturday together … going go-karting during the day..
and hitting up Playhouse in Hollywood at night..
It’s interesting … the two were rumored to have hooked up all the way back in February, but nothing has been mentioned about the would-be pair since.
Rob is dating singer Rita Ora and the two recently got each other’s names tattooed on their hands.
Ri Ri makes moves don’t she??
