Pretty girls? More like mean girls!

After Iggy Azalea backhandedly slammed her "Pretty Girls" track with Britney Spears, the pop princess took to her Twitter to let Iggy know who's boss.

A fan recently tweeted at Iggy and asked why the duet wasn't doing as well as everyone predicted, to which Iggy replied, "its difficult to send a song up the charts without additional promo and tv performances etc. unfortunately I'm just featured.... would have enjoyed performing it alot, i think it got off to a powerful start. but you need content to compete in 2015."

After a number of commenters blew up Iggy's feed, she continued:
    "my comment is factual, it applies to any song. I dont have to suck the womans a**hole 24/7 to be her friend, do i? bye girls. Genuine friends have genuine opinions. Its possible & healthy to have a differing thought without it being bitchy or shade. i really love the song, and actually never said anything negative, only that i think there was room to do more with it. its really not something you should feel mad or aggressive about. i love the song and i think Britney is great. why be angry?"

Well, it seems like Britney was a bit angry! The pop superstar tweeted, "Can't wait to get back to Vegas. So thankful I have shows for the rest of the year to look forward to ... #YouWantAPieceOfMe." "Piece of Me" IS a famous Britney tune, but let's keep in mind that Iggy's Great Escape tour was cancelled earlier this year, so this is clearly a big jab at the Aussie starlet.

It's Britney, b*tch!