Miley Cyrus has taken a swipe at Katy Perry after their infamous kiss.
The pop stars locked lips when Perry attended the Wrecking Ball singer's show in Los Angeles in February.
While in Sydney this week to promote her upcoming Australian tour, Perry joked that the front row smooch cam as a surprise and was concerned about where Cyrus' mouth had been.
"I just walked up to her to give her like a friendly girly kiss, you know, as girls do, and then she like tried to move her head and go deeper and I pulled away," Perry told the Seven Network on Wednesday.
"God knows where that tongue has been. We don't know, that tongue is so infamous."
But Cyrus, known for sticking her tongue out in photos, hasn't taken the remark lying down. She took to Twitter on Thursday to trade barbs.
"Girl if ur worried abt where tongues have been good thing ur ex boo is ur EX BOO cause we ALL know where THAT (tongue) been," Cyrus tweeted, dragging Perry's rumoured ex-boyfriend John Mayer into the fight.
Perry and Mayer reportedly split last month amid rumours Mayer had just proposed.
Star magazine reported on Thursday that Mayer had a "fling" with a Soul Cycle instructor last May, possibly leading to the split.