Justin Bieber only having fun with Selena Gomez?

Singer-cum-actor Justin Bieber has sparked serious concern about his relationship with girlfriend Selena Gomez. On July 13, the Canadian teen sensation posted a cryptic message on his Twitter page, which generated speculations that he is not serious with the Hollywood actress.

On Wednesday afternoon, Justin Bieber tweeted, "I'm not sayin your the one girl, I'm just here to have fun girl." But it is reported that the 17-year-old heartthrob could be referring to the lyrics of a song or a quote in the tweet instead of his relationship with Selena.

Later that day, Justin Bieber was joined by Selena Gomez as he attended the 2011 ESPY Awards. They arrived to the event separately, but the couple sat together in the audience in the Nokia Theatre LA Live. He even put his arm around her shoulder as they posed for photos together in their adjacent seats.