Miley Cyrus has taken a swipe at Katy Perry after their infamous kiss.

The pop stars locked lips when Katy attended the Wrecking Ball singer’s show in Los Angeles late last month.

The Roar singer later joked she was stunned to receive the front row smooch and was concerned where Miley’s mouth has 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,” Katy revealed during an appearance on Australian TV programme Sunrise this week.

“God knows where that tongue has been. We don't know! That tongue is so infamous!”

But Miley, known for sticking her tongue out in photos, hasn’t taken the remark lying down. She logged onto Twitter Thursday ready 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,” Miley wrote, dragging in Katy’s rumoured ex-boyfriend John Mayer (sic).

Miley was in the middle of performing her track Adore You when she saw Katy in the crowd and leaned in for the embrace. She previously joked about the smooch on the micro-blog.

"I just kissed a girl and I really liked it a lot," she tweeted, referencing Katy’s smash hit I Kissed A Girl.

It’s unclear where John and Katy’s relationship stands at the moment.

The singers have been dating on and off since 2012, and apparently broke up again last month amid rumours John had just proposed.

America’s Star magazine reported Thursday serial dater John had a “fling” with a Soul Cycle instructor last May, possibly leading to the split.