Taylor Swift's performance at the iHeartRadio Music Festival over the weekend went off without a hitch -- for the most part. A minor wardrobe malfunction proved that even those most put-together celebs can run into clothing mishaps. Luckily, even though a fan tugged too hard on Swift's dress and caused the strap to come undone, the country star was saved any embarrassment by the sequined shirt she wore underneath her dress. Otherwise, there could have been a Janet Jackson-like slip-up. Phew!