Looks like JOHN MAYER got his birthday wish on Wednesday night - ex-girlfriend JENNIFER ANISTON.
The couple split in August but, amid claims they've reconciled, Jen helped John celebrate his 31st birthday in Los Angeles.
The actress showed up at members-only restaurant and cigar club the Grand Havana Room and stayed long after midnight to help Mayer ring in his birthday.
An onlooker says, "They seemed to be having a great time."
It was the couple's second outing in Los Angeles this week, following a dinner with friends the night before at the Sunset Towers. Mayer and Aniston are also planning to dine out together again tonight.
Sources say the couple has booked a table at a top West Hollywood restaurant.