One of the major rules of MCing is this: never stop rapping. Even if the track messes up during a performance or a rapper forgets a word or two, the show must go on.

Apparently, nobody told this to Iggy Azalea because during the season 18 finale of 'Dancing with the Stars' Tuesday night (May 20), she committed a major flub at the start of her performance and abruptly stopped.

The Australian native was performing her hit song 'Fancy' with Charli XCX and right after she spit the first line, "First thing's first, I'm the realest," it was apparent something was wrong when she was rapping in sync with her ad libs. This threw Iggy off completely.

As she tried to work around the issue, she only seemed to get more lost. Then she did the unspeakable. At least in hip-hop realms. She stopped rapping. "I'm so sorry, but there's something wrong with my ear," she admitted. But no one seemed to pay her any mind, and the backup dancers just continued to dance. Evidently, they were the only ones aware that you can't stop performing in the middle of a live show.

Once the Hustle Gang affiliate realized that the song wasn't going to start over, she took out her earpiece and spit her rhymes without it. Again, something any true MC would have done in the beginning. Maybe T.I. should have taught her better.

After the performance, she issued an apology via Twitter "I am so sorry guys," she wrote. "My in ears messed up and I couldn't hear the track. The dramas of live TV. S--- happens. Still really enjoyed it."

Hopefully, she'll know better the next time something goes wrong at one of her shows.