Maniston Make Public Debut

Jen Aniston and John Mayer went to their first public event together Thursday night.

They joined Courteney Cox and David Arquette — who celebrated their nine-year anniversary that night — at a humanitarian event at L.A. steakhouse STK. (See more photos here.)

A witness tells Usmagazine.com that Aniston and Mayer “had their arms around each other. She was rubbing his back and whispering into his ear. They were touching each other non-stop all night.”

The bash was in honor of Jeffrey Sachs — who is known for his charity work with Angelina Jolie and is pals with Aniston’s ex Brad Pitt.