And just days after Aniston returned, they were a couple no more, sources confirm to PEOPLE.
"They had some disagreements and decided to not continue to see each other," says one source. "Jen is moving on with her life like she always does. She seems happy."
A second source says Mayer broke up with Aniston after she returned from Europe.
In the last few weeks, the former Friends star has been spending time with her close pal Courteney Cox Arquette and her yoga instructor-friend Mandy Ingber, while Mayer has been busy getting his new house ready and working in the studio. Then E!'s Marc Malkin reported rumors of a possible split.
Previous BreakupThis is not the first time Aniston, 40, and Mayer, 31, have split. In August 2008, they called it quits. At the time Mayer held an impromptu press conference outside his gym in New York, explaining to the media: "I ended a relationship to be alone because I don't want to waste somebody's time if something's not right."
Still, lately the couple have seemed happy together. They met at a 2008 Oscar party last year, and were one of the hottest couples at this year's show after a surprise appearance by Aniston as a presenter, with Mayer as her date. Mayer later said he was there to offer moral support to his girlfriend.
In a recent interview, Aniston said she didn't believe any relationship was perfect, or was meant to last a lifetime. "Whoever said that every relationship has to last forever?" she told the U.K.'s Mail on Sunday's You magazine. "That's hoping for too much."
Reps for Aniston and Mayer had no comment.
Additional reporting by LIZ MCNEIL
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