Not having it! Britney Spears had little tolerance for a fat-shaming heckler on Wednesday, April 15.

The pop star, 33, returned to the stage at Las Vegas' Planet Hollywood Resort and Casino to continue her Piece of Me residency show after a brief hiatus, but was met with unkind comments from one audience member upon her reprise. See photos from Piece of Me's opening night.

As seen in video from the show, Spears strutted her stuff on stage in a figure-hugging corset, stepping into a performance of her 2011 single "Till the World Ends." When she turned her back to the crowd, however, a heckler reportedly shouted "Fat bitch!"

The insult was seemingly loud enough for the star to hear, as she responded into her microphone, spitting back, "F--king a--holes!"

Proving that the show must always go on, Spears didn't let the rude moment throw off her game. She joined her army of backup dancers and continued the performance, working it as she belted, "This kitten got your tongue tied in knots, I see / Spit it out cause I'm dying for company / I notice that you got it / You notice that I want it / You know that I can take it / To the next level, baby."

The "Work Bitch" singer, who has Las Vegas shows scheduled through September, has yet to comment on the incident. Watch her quiet the heckler in the video above!