Miley Cyrus has slammed Katy Perry on Twitter.

The pair locked lips when Miley performed in Los Angeles recently, but Katy said on Australian TV earlier this week she pulled away when "Wrecking Ball" star tried to take it further, saying, "God knows where that tongue has been. We don't know! That tongue is so infamous!"

Miley, 21, hit back on Twitter today, slamming notorious ladies man John Mayer, who recently split with Katy. "Girl if ur worried abt where tongues have been good thing ur ex boo [boyfriend] is ur EX BOO cause we ALL know where THAT [tongue] been [sic]," she wrote. Trying to soften the blow, Miley then added, "Dontchyouuuu act like you didn't lurvvvvv it @katyperry [sic]."

After their kiss on February 22, Katy shared an aftermath photograph, which features the "4x4" singer with her mouth hanging open in shock and Katy covering her mouth with her hand, and captioned it, "And after! I adore you @Miley Cyrus."

Katy, 29, and John split last month, blaming their conflicting schedules, but since then friends have accused the guitarist of "sketchy" behavior. "The last time they broke up John won [Katy] back by making a ton of promises. He was going to put her first, but now he's falling back into his old patterns. Like, he shuts off his phone and disappears all day and night - he says it's because he needs alone time, but it's sketchy for sure," a source said.

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