Spears, shot an elevator scene in which she is disguised in a black hoodie, a source told Us.
Once in the elevator she realizes she is trapped and cannot get out, she "starts to kick the wall and hit things," the source added. "At one point she screams into the camera."
In a state of panic Spears takes off the hood, revealing her long blonde locks, looks straight into the camera and says her famous line "It's Britney, [expletive]."
Spears has been keeping herself busy these days with recent appearances on "How I Met Your Mother" and working on her upcoming album.
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After Britney's performance, which pop star would you like to see make a guest appearance on "How I Met Your Mother"?
Jessica Simpson
Madonna
Mariah Carey
Beyonce
Lindsay Lohan