The pop star, who spent just 55 hours married to her hometown sweetheart Jason Alexander at the beginning of 2004 after they exchanged vows in Sin City, will be a bridesmaid at a pal's weekend wedding.

The excited Toxic singer has posted a video of herself heading to Vegas for the nuptials.

"My best friend is getting married!" she squealed as her manager shot the footage of Britney and another friend during a drive through the desert.

Spears added the caption: "go try on that bridesmaid dress lol (laugh out loud)."

The singer has made a home in Las Vegas in recent years - she stages her Piece of Me residency at the Planet Hollywood resort.