The 'Wrecking Ball' singer got all huffy after Katy was asked during an interview in Oz about the moment Miley jumped off stage during a show on her current Bangerz tour to plant a smacker on Katy, who was sat in the front row.
And it seems Katy kissed a girl but didn't like it, saying she tried to pull away as 'God knows where that tongue has been'.
Well, to be fair it is usually covered in fur.
Cue Miley taking to Twitter to blast Katy and have a pop at her ex, John Mayer, who she split from last month.
"Girl if ur worried abt where tongues have been good thing ur ex boo is ur EX BOO cause we ALL know where THAT [has] been."
Translation: You're ex has been around a bit.
Girl if ur worried abt where tongues have been good thing ur ex boo is ur EX BOO cause we ALL know where THAT 👅 been pic.twitter.com/IO6KwRzw2y— Miley Ray Cyrus (@MileyCyrus) March 6, 2014
Miley then added a lovely little drawing of the moment they locked lips, writing: "Dontchyouuuuu act like you didn't lurvvvvv it @katyperry."
— Miley Ray Cyrus (@MileyCyrus) March 6, 2014
Well, after watching the video (below) of them sharing saliva, we think Miley may have a point.
Over to you Katy...