When Jennifer Aniston headed out for dinner on Nov. 13, she seemed to have just one person on her mind: John Mayer. At NYC restaurant La Esquina, the on-again couple "were sharing their food and acting like teenagers," says a fellow diner.

But while Jen, 39, acts like a woman happy to live in the present, she's made it clear she's still struggling to cope with the past. Jen and John are heating up, but Jen may be causing problems for her ex, Brad Pitt, and Angelina Jolie.

For more on Jen's battle to free herself of Brad and Angelina, pick up the latest issue of Life & Style, on newsstands now!

Photo Credits: WireImage; JPIStudios