Don’t mess with Britney, bitch. Iggy Azalea learned a lesson when she chided Spears for not promoting their collaboration “Pretty Girls.”

During a Twitter Q&A, a fan asked the Aussie rapper why the single failed to take off (“Pretty Girls” peaked at No. 29 on the Billboard Hot 100).

Iggy responded, saying it was beyond her control since she was only a featured artist and there was only so much she could do.

But Iggy insisted her comments weren’t a dig at her fellow blonde. “My comment is factual, it applies to any song,” she tweeted. “I dont have to suck the womans asshole 24/7 to be her friend, do i? bye girls.”

But Britney bit back, responding to Iggy’s comments with a shady tweet of her own. “Can’t wait to get back to Vegas. So thankful I have shows for the rest of the year to look forward to… #YouWantAPieceOfMe,” said the pop superstar, who is headlining her “Piece of Me” residency at Planet Hollywood in Las Vegas.

It’s no secret that Iggy pulled the plug on her “Great Escape Tour.”