Microblogging service Twitter played a big part in Aniston's decision to split with musician boyfriend Mayer, sources claiming to be Aniston's friends told celebrity mag Star.
Instead of spending time with his girlfriend -- voted the no. 2 sexiest woman on Earth last year -- Mayer would say he was busy, the sources said. But then he spent hours posting "tweets" -- online messages detailing his innermost thoughts -- each in 140 characters or less, Britain's Telegraph reported.
"Jen was fuming," a source told Star. "There he was, telling her he didn't have time for her and yet his page was filled with Twitter updates.
"Every few hours, sometimes minutes, he'd update with some stupid line. And in her mind, she was like 'He has time for all this Twittering, but he can't send me a text, an email, make a call?'."
When Aniston, 40, confronted the "Your Body is a Wonderland" crooner, Mayer, 31, didn't deny sneaking tweets, the source said.
"He took the break-up like a man," according to the Telegraph.
Of course, there have been other break-up theories.
Last week, an "insider" told OK! magazine that Aniston ditched her man because he didn't want to father her child.
A person who claimed to be Mayer's friend told the magazine that it was Mayer's music that shut the door on the couple.
"They left the door open to give it another go. John's number one priority is his music. Which is all-consuming for him," the source said.
No matter what happened, the break-up took its toll on the guitarist - Mayer's Twitter feed said it all, the Telegraph reported
"This heart didn't come with instructions," one update read.