Britney -- Abs-olutely Perfect

12/2/2008 10:39 AM PST
What Britney lacked in dance moves on "Good Morning America," she definitely made up for in the ab department.

Spears brought her now infamous "Womanizer" strutting/arm-flailing routine to a new song, "Circus" but her stomach made for quite the distraction.

Another welcome distraction -- the birthday girl's fam, who sat in the second row.