Britney Spears slams back after Iggy Azalea blames her for 'Pretty Girls' flop

Don't mess with Britney, b----.

After Iggy Azalea blamed Britney Spears for their recent 'Pretty Girls' flop in a series of tweets, Britney, 33, fired back with some shade of her own.

That's got to be a swipe at Iggy for her recently cancelled tour, right? Well, Iggy did start this one. 

After a fan tweeted her words of consolation over the poor chart performance of the Britney-Iggy collaboration, the 25-year-old rapper tried to explain, at Brit's expense.

If there was any doubt that she was making a not-so-subtle dig at Britney, she later delivered this zinger:

Yikes! That's pretty harsh, especially considering how chummy Britney and Iggy have seemed to be in recent months, both in the video and in the press. They even performed the song together at the Billboard Music Awards. Watch it below.

Unfortunately, Britney's regular Vegas gig probably prevented her from doing more, to Iggy's regret and extreme annoyance.

"I would have enjoyed performing it a lot, I think it got off to a powerful start," she tweeted. "But you need content to compete in 2015."

Exactly. Maybe Iggy should consider that 'Pretty Girls' just wasn't particularly good content, and that's why it peaked at a lowly No. 27 on Australia's ARIA chart.

Perhaps she's seen the light. Her tweets appear to have been deleted from her Twitter account.

Better luck next time, ladies…if there is a next time.