Inside Jen's Birthday Week

(Photo: Splash News Online) Jennifer Aniston sure knows how to stretch out her birthday celebration!

On Wednesday, Jen turned the big 4-0, and a source tells People.com that on the night before, the actress spent a quiet night at her new Beverly Hills home with boyfriend John Mayer. The next morning, on her actual birthday, they had a small birthday celebration together.

That evening, a small group of friends celebrated at Jen's home. Wally's Wines and Spirits delivered champagne and wine for the gathering which included Mayer.

Earlier RadarOnline.com told you about Jen's big "A-list" birthday bash she threw for herself at her new home last weekend.

Party on, Jen!