Where was she!?

Last night John Mayer dined at Loteria Grill in Hollywood, and rather than bringing his busty babe of a girlfriend, the 34-year-old singer rolled with several friends. While we're sure all is well with the hot new couple, there's a rumor circulating on the web that John is chasing after Katy in an attempt to get closer to her BFF Rihanna.

“They really hit it off,” a source tells the National Enquirer of one of their first meetings at a 2009 music industry party in New York. “John was smitten. He tried to lure her back to his place on several occasions, but Rihanna just laughed him off, saying she wasn’t his type. That only made him want her more ... Rihanna has ALWAYS been a fantasy chick for John.”

“Katy has no idea just how hard he tried to score with Rihanna,” another source added. “Now, her pals are worried she’s headed for heartache.” Yikes! We doubt that's true, but will Katy's romance with the serial dater last?