The stars of Haim feared they would be slapped with a heavy fine over their televised Glastonbury appearance as they thought their bassist had accidentally flashed her breasts to the Tv cameras.
The girl group was performing on the first day of the British music event last month (Jun13) when diabetic Este Haim's blood-sugar ran dangerously low, prompting her to run off stage to seek help.
Este's sisters have now revealed they didn't realise she was ill when they saw her make a quick exit, and thought she had suffered a wardrobe malfunction onstage.
In an interview with Pete Donaldson on Britain's Absolute Radio station, bandmember Alana told Este, "I honestly thought that your boob had popped out and that's why you were freaking out so much."
Este added, "She really did - she must have been thinking 'Oh my God my sister has pulled a Janet Jackson and we're going to get fined'. Luckily this wasn't the case."
Janet Jackson caused a furore in 2004 when her bare breast was accidentally exposed on live Tv during her performance at the Super Bowl halftime show.