What lead to Jennifer Aniston’s latest split from on-again/off-again BF John Mayer? Twitter.

Jennifer was reportedly driven to end her relationship with John Mayer because of his Twitter “obsession”, Star Magazine tipsters claim.

A pal of the 40-year-old actress claims Jen only discovered that the musician spent hours on the social networking site when he claimed he was too busy to get in touch with her.

“John suddenly stopped calling her or returning her e-mails and when she would finally catch up with him, he’d say, “I’ve been so busy with work. ‘I’m sorry I haven’t had time to call you back,” an inside source says.

“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 e-mail, make a call?”

“Jen was fuming….”