01/17/2012 09:03 am ET

Christina Aguilera, Boyfriend Matthew Rutler Party In San Diego (PHOTO)

What a way to turn 4! After treating her birthday boy, son Max Bratman, to a day at Legoland, Christina Aguilera took him to the Hard Rock Hotel San Diego, where she checked into a luxe Rock Star Suite with boyfriend Matthew Rutler and several friends.

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