First Lady Michelle Obama is celebrating her 48th birthday tonight with her husband and close friends at BLT Steak in Washington, D.C., just blocks from the White House.

Tonight's dinner continues a birthday tradition. In years past, the first lady has celebrated at some of D.C.'s finest restaurants, including Wolfgang Puck's The Source and Restaurant Nora.

The president, who is two years older than Mrs. Obama, joked about his wife's age today. "When we first married, it was a little controversial that she was 20 years younger than me, but now it seems to have worked out O.K.," the president quipped.

"I'm 48," the first lady proudly declared to the audience.