Clean-living pop stars The Jonas Brothers were left blushing on the set of their new TV show when a group of female fans flashed their breasts at their idols.

Kevin, Joe and Nick Jonas are famous for vowing not to have sex before marriage, and they wear purity rings to show how serious they are about remaining virgins until they wed.

But a group of daring girls decided to put their chastity to the test when they showed up on location in Los Angeles, where the boys were filming for their show Jonas, holding up a large sign that read: "Take us... We're yours!"

The group smiled at the cheeky banner - but covered their eyes in embarrassment when the fans dropped the sign to reveal their bare breasts, reports the National Enquirer.

Security guards immediately ordered the girls to cover up and sent them on their way.