John Mayer helps actress celebrate

Jennifer Aniston marked turning 40 with a quiet night in.

The actress invited her closest pals and boyfriend John Mayer, 31, to her Beverly Hills home.

Earlier in the day, Jen – who also got together last Saturday with pals  Sheryl Crow, 47, and Courteney Cox-Arquette, 44 – was seen taking a delivery of champagne and wine to quench her guests’ thirst.
 
‘They had a small birthday celebration at her house Wednesday morning,’ a source tells People.

SEE GALLERY Jennifer Aniston at 40>>