They were spotted looking very happy together at the Oscars but actually they split before the event. It was just an acting.
This is what The Enquirer reported:
And now, the Oscar for “Best Phony Couple” goes to…(drum roll)…Jennifer Aniston and John Mayer, who masqueraded at the Academy Awards as a loving couple - despite their top-secret bustup only days before - just because insecure Jen suddenly panicked over confronting sexy ex Brad Pitt and Hubba Hubba Angelina Jolie without a devoted hunk of man candy dangling at her arm.
But then later, after chilling a bit, horrified Jen suddenly remembered a major date she’d forgotten in all the emotion. Tracking John down, she gasped: “Omigod! What about the Oscars! You’ll still go with me to the Oscars…won’t you?”
Luckily, the singer hadn’t blabbed about the breakup to anyone -and, knowing she’d hate solo-ing it down the red carpet under Angelina’s baleful glare - he gallantly told Jen, “Hey, I wouldn’t let you down. I’d be happy to escort you.”
[From The National Enquirer print version, April 13, 2009]
Source