BRODY JENNER HAS A CRUSH ON RIHANNA...

Brody Jenner's job was to introduce Rihanna last night, but according to Isthishappening.com sources backstage he may have been trying to take his job a little to seriously!! Brody introduced her as, "the future Mrs. Jenner," and backstage he couldn't stop hitting on her... Our source says, "Brody and Chace [Crawford] kept going up to her, trying to make conversation and get her to go out to party [at Ultra] later."

Too bad Chris Brown wasn't there to kick his ass!!