Justin Bieber concert performance singing stage microphone costume white sunglasses Mr. Paparazzi

Justin Bieber wasn't itchy, and he wasn't going for Michael Jackson's signature crotch grabbing move, so what on earth was he doing at the Liverpool Arena in the UK last night?!

It turns out the 17-year-old Baby singer was fixing a mid-performance wardrobe malfunction:

Justin Bieber concert performance singing stage microphone costume white sunglasses

Oops ... looks like the world's biggest male pop star is guilty of leaving his fly down every once in a while!