It happens to the best of us, Britney - there you are, lip-synching your way through a song mid-gig during your Las Vegas residency, when BAM! - wardrobe malfunction.

Spears was 'singing' her song '3' during a gig last Thursday when disaster struck and the back of her figure-hugging onesie opened.

Her army of dancers took turns queuing up behind her to try to zip it back up - and through it all, her voice didn't falter. Not even once. She didn't miss a single note as smiled with a crazed look in her eye and did some improvisational dance moves with her arms. What a pro, eh?

Besides all of the costume kerfuffle, what has watching this video taught us? Never go to see Britney Spears again.

Watch it below: