Christina Aguilera's Birthday Boy: Son Max Turns 4!

Christina Aguilera and her son Max celebrated his fourth birthday this past week at California's Legoland, and the singer shared the birthday news with her Twitter followers later that day:

"Spent today at Legoland with the love of my life. Happy bday Max!" 

Aguilera's boyfriend, Matt Rutler, joined in the birthday fun along with a small group of family and friends. Legoland supplied the birthday cake for the 4-year-old - a vanilla cake with vanilla frosting and LEGO brick décor.

Picture: Legoland/People.com