Miley Cyrus Miley Cyrus

Katy Perry kissed a girl and, apparently, she didn't like it.

Perry was in the audience during Miley Cyrus' concert in Los Angeles last month when Cyrus left the stage and walked into the crowd to plant a big one on the "California Gurls" singer. However, when Perry recently appeared on the Australian talk show Sunrise, she complained that Cyrus took their kiss too far.

PHOTOS: The biggest celebrity feuds

"I just walked up to her like a friendly girl kiss, you know, as girls do," Perry said. "And then she like tried to move her head and go deeper and I pulled away. God knows where that tongue has been!"

Cyrus didn't take too kindly to the diss, and blasted Perry on Twitter with a set of photos from Perry's appearance on Sunrise. "Girl if [you're] worried [about] where tongues have been good thing [your] ex boo is [your] EX BOO [be]cause we ALL know where THAT [tongue has] been," Cyrus tweeted in reference to Perry's on-and-off boyfriend John Mayer, whom she allegedly split from last month.

Cyrus then posted a cartoon illustration of the duo kissing with the caption, "[Don't you] act like you didn't lurvvvvv it." Perry later responded, "Oooo gurrrl I'm gonna give you the BIGGEST spanking when I see you in the UK!"

What do you think of their feud?