Christina Aguilera celebrates 31st birthday with 'The Voice' mentors

Christina Aguilera has celebrated her 31st birthday in Los Angeles with family and 50 close friends, including her fellow The Voice mentors.

The Burlesque popstar was joined by Adam Lambert and Blake Shelton along with his wife Miranda Lambert, reports US Weekly.

Cee Lo Green, who also serves as a mentor for the NBC singing competition show, was apparently not at the party.

Guests dined and played board games at her party, while Aguilera's boyfriend Matthew Rutler surprised her with a Marie Antoinette cake.

A source claimed: "Christina loves costumes and period pieces so it was perfect. Everyone had a great time."

Earlier this month, it was reported that Aguilera was thinking of proposing to Rutler.

"He gets a little embarrassed, but it'! s obviou s they've talked about it. It's coming soon," a source claimed. "She wants to start over and thinks that asking him to marry her is the way to start."

Watch the music video for Christina Aguilera's 'You Lost Me' below: