Aaand, here we go again!

Britney Spears has been accused of lip-synching during a performance at her Las Vegas show.

The singer was caught out when a fan uploaded a video of Britney singing the song Perfume, which was written by Sia.

However, it sounds like Sia did a lot more than just write the song, as many are claiming the vocals you can hear are actually that of the Australian singer/songwriter, and not Britney’s…

Unfortuntely for Britney, this is far from being the first embarrassing situation with regards to her singing. Just recently, an un-autotuned version of Alien was leaked, and let's just say, it's baaaad. Here's a reminder: 

We think if any other singer did this we would be outraged, but it's Britney, and we love her anyway.