Source: John Mayer and Jennifer Aniston "Are Not Dating Again"

Tabloid rumors swirled this week that John Mayer is back on with Jennifer Aniston.

But during his concert Tuesday in Irvine, Calif., he took time out to set the record straight, MTV reports.

"I'm completely single!" he told the crowd.

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Then, in typical Mayer style, he launched a TMI rant about his love life.

Mayer, 32, told the crowd he has a morning ritual of watching naughty Internet videos. (A specific brunette has been his latest obsession.)

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Sniped the singer, "That is the dirty truth."

As for those Aniston reports, an insider tells UsMagazine.com: "John is still friends with Jen, but they are not dating again. She was not at the Hollywood Bowl show he played, but it would not mean anything if she were. They remain friends but are definitely not back together."

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Mayer's rep does not comment on his personal life.