Jennifer Aniston & John Mayer in L.A.: Just Friends?

By Jennifer Garcia

10/15/2008 at 06:10 PM EDT

After spending time together in New York last weekend, Jennifer Aniston and John Mayer turned up in Los Angeles for a night out with friends.

Aniston, 39, and Mayer, 30, and three pals arrived late Tuesday night at the Sunset Tower Hotel for dinner at the Tower Bar, where Aniston nibbled on a grilled chicken salad while chatting with the group.

"They left out the back of the hotel and were very discreet," says a source. "Jen was leading but John walked very closely behind her when they left."

Earlier in the evening, Aniston – sans Mayer – supported pal Courteney Cox Arquette at the Glamour Reel Moments premiere.

• Reporting by PERNILLA CEDENHEIM