A mental breakdown, a shaved head, two babies, a very ugly public divorce and living under the tight supervision of her father is not enough to teach Britney Spears a lesson. As soon as Jamie Spears turns his back, she is getting busy with a another back-up dancer.

Has she already forgotten what messing around with a back-up dancer named Kevin Federline did to her life and career?

According to a well-placed tour source, while father Jamie was tending to business in L.A. late this month, Britney hooked-up with a 21 year-old dancer.

“Britney was a bad girl,” says our insider. “Literally as soon as her dad left, she started getting cozy with a dancer named Gio. It wasn’t serious. They had a few romantic interludes, and she bought him a few things — a pair of shoes and some clothes — even though she’s on an allowance.”

But now that Jamie’s back with the “Circus” tour and casting a watchful eye over his daughter again, Brit’s romance has cooled. “Britney was definitely getting jiggy there for a hot minute, but they’ve slowed down since Jamie got back in the picture,” says the insider. “It’s basically over now.”

And just for fun…enjoy this video of Britney screaming out her favorite word…”bitch”…around the :04 mark.