Katy Perry is currently dating John Mayer, but if things had gone a little differently, she could've ended up dating a much more famous — and much older — musician: Mick Jagger.

Appearing on Australia's NovaFM, Katy was asked to confirm that she sang background vocals on "Old Habits Die Hard," a song that the Rolling Stones frontman recorded for the movie Alfie.  Katy said that she did it before she was famous, when she was about 19, and then dropped a bombshell about Jagger.

"I actually went to dinner with him one time and he hit on me when I was, like, 18," she revealed.  When the deejay expressed shock, Katy added, "Yeah, but that was a long time ago and since then he's been very kind. And I got to sing 'Beast of Burden' with him on his stage, on the Rolling Stones tour."

When asked by the deejays how you turn down someone like Mick Jagger, Katy laughed, "Well, you bring a friend and then they [have sex with] them…You sacrifice your friend!"

Katy also said it wasn't unusual back in the day for her to sing background vocals for famous stars, because she was just trying to make ends meet while waiting for her big break.

"I did a lot of stuff behind the scenes, as we do, coming up, y'know?," she explained. "I did lots of background vocals, I did background vocals on a Miley Cyrus record!  I did all that stuff, just to hopefully get by on Taco Bell money."