Paris Hilton has apologized to her close friend Kim Kardashian after joking about her curvy backside. The socialite said during a Las Vegas radio show Monday, "I would not want [Kim's but] - it's gross! It reminds me of cottage cheese inside a big trash bag." But, Paris realized she had gone too far while watching herself on the internet and mended her mistake rapidly. She told tells In Touch magazine, "I was just joking around and I made a stupid joke. I felt really bad afterward, so I contacted Kim and apologized. It was a silly thing to say. Kim's hot!" Kim acknowledged the apology and replied, “Paris and I have been friends since we were kids and I'm glad she made the effort to say she's sorry."