Jennifer Aniston & John Mayer: Back On or Just Friends?!

Is Jennifer Aniston waiting in the wings for John Mayer?

Celeb tabloids have been having a field day in the last week or so with claims that the former lovebirds have recently been spending some time together…

Just last night, sources say they saw The Switch star in the wings watching Mayer's concert at the Hollywood Bowl.

"He keeps looking, smiling, smirking and winking at her—especially during 'I Don't Trust Myself With Loving You,'" one of the sources emailed me during the concert.

But was it Jen?

A Mayer insider insists she was not there (but does say they are still friends), while our source said, "If it wasn't Jen, she has a real good doppelgänger. She was in the typical jeans, black sweater with a wrap and her straight hair."

Well, sounds like Aniston's fashion may be catching on with others because, her rep said, "Jennifer was not at John's concert. It must have been a doppelgänger."

Meanwhile, the New York Post reported today that Gossip Girl star Michelle Trachtenberg "cozied up" to Mr. Mayer recently at Soho House in Los Angeles. A rep for the actress insists they're just friends. "They've known each other for years," the rep said. "They ran into each other and said hello."