It's a celebrity's worst nightmare ... unless it was planned!
From Starpulse: "Hayden Panettiere attended the Golden Globes HBO after party in 2011 wearing a blue dress that showed off just a little more than she intended - her nipple cover. We give her credit for trying to avoid showing off her nipple, but her plan backfired."
Click through to see and for more celebrity wardrobe malfunctions. Can you tell which ones were intentional?