It was the song that was supposed to be the summer hit of 2015: Britney Spears (who's shifted 100m albums in her 15-year career) and Iggy Azalea (who's the hot, young rap artist to collaborate with) came together and produced Pretty Girls.
They performed at the Billboard Music Awards, and the duo pushed their tune on social media. They have, after all, a combined following of some 47.5m (42.3m for Brit Brit; and 5.3m for Iggy) on Twitter.
The accompanying video – a bizarre, Eighties-inspired dance-fest – was released to much fanfare too. It notched up 78m views on YouTube, but was still widely panned as ridiculous.
The song itself hardly fared much better: in Iggy's native Australia, it peaked at No.27. In the US, it reached No.23. In the UK, it made No.16, while in Ireland it limped to No.60.
And today, Ms Azalea was asked by a fan why she thought the song did so badly.
"It's difficult to send a song up the charts without additional promo and tv performances etc. unfortunately I'm just featured," the rapper tweeted in response, effectively washing her hands of the song's poor showing.
Even more cutting, she then concluded with: "I dont have to suck the womans a**hole 24/7 to be her friend, do i?"
However, this evening she posted two more tweets – seemingly in response to the negative backlash to her earlier claims.
"Genuine friends have genuine opinions," she wrote. "Its possible & healthy to have a differing thought without it being bitchy or shade."
The Fancy hitmaker had earlier revealed to Access Hollywood that she wanted to take the lead on Pretty Girls, with Britney instead being the featured artist.
"I rewrote parts of it and it became my song, and I tried to make it all mine and keep it," she explained. She added, however, that Ms Spears then came knocking. "So I swung it back her way because she's Britney Spears, you have to do that," she said.
"She gets whatever she wants. She has her verses I have my verse, but it's not just me kind of popping in it."
It's been a turbulent time for Ms Azalea. She had to scrap her world tour, as well as a high-profile performance at the Pittsburgh Gay Pride Show – the latter when old tweets surfaced that seemingly showed her using homophobic language.
Still, the rapper recently got engaged: namely to professional basketball player Nick Young, who popped the question with a huge 10.43ct ring worth €450,000.
