Nicki Minaj in the Anaconda video. Iggy Azalea and Jennifer Lopez in Booty. Kim Kardashian and the champagne flick. Jen Selter. Belfies. Yes, belfies. Plus, Amy Schumer's send-up of this all-consuming butt obsession, Milk Milk Lemonade. It's inescapable, and if you're blessed with a peachy, perky posterior, it's probably heaven. But what if you aren't?