The Cyrus gets tongue happy on stage.
Look look! She's kissing a girl!
Maybe she's been talking to Katy Perry and wondered whether she might like it too.
And here's the video:
Miley was performing her new single 'Can't Be Tamed' on Britain's Got Talent.
Er, Miles, did you not notice all the fit men around you to choose from? Or is this a new-boyfriend-Liam-rule that says you can only kiss other girls?
We're wondering what Simon made of it all...
What do you think? Do you like the song? We just hope she doesn't go the way of Britney just after her Madonna snog.