Christina Aguilera: Happy Birthday, Max!

Christina Aguilera takes her son Max to Legoland for a special birthday celebration on Thursday (January 12) in Carlsbad, Calif.

The 31-year-old entertainer’s son turned 4 that day! Happy birthday, Max!!! For a special birthday treat, Christina and Max enjoyed the attractions of the theme park, and the duo even drove a Legoland boat!

PHOTOS: Check out the latest pics of Christina Aguilera

Christina, who is on the cover of Marie Claire magazine’s February issue, told the publication she is happy to see 2011 in the past.

“That was a rough year…Between my divorce and the other things I went through, a lot happened. It’s hard for anyone to go through that in public. But when you’re a celebrity and under a microscope, it’s 58 million times harder,” Christina said. “I grew an even thicker skin after that hard year.”

FYI: Christina is wearing an Autumn Cashmere sweater.