London: Teen pop star Justin Bieber approached R&B star Rihanna five times to talk to her at the Billboard Music Awards but was stopped by her security guards.
The 17-year-old was mortified at the rebuff because he thought he and Rihanna were friends after bonding with her at the BRIT awards earlier this year.
"Justin thinks Rihanna is the most beautiful woman and supremely talented. He is in awe of her. Justin is just a red-blooded teenager, he can`t help acting like a love-sick puppy dog when he`s around her. The pair were chatting as Justin`s girlfriend Selena looked on, scowling. Then Rihanna got dragged away by a couple of her friends," a source said.
"The pair resumed their chat later but when Justin went to talk to her at the show`s climax her security blocked his path, telling him to `leave it`," the source added.
The `Baby` hitmaker was accompanied to the bash by girlfriend Selena Gomez which took place at Las Vegas` MGM Grand Garden Arena.
However, Bieber appears to be over his disappointment as he has jetted off on holiday to Hawaii with Gomez.