Paris Hilton has apologized to Kim Kardashian for telling a radio show in Las Vegas yesterday that she wouldn't want to have Kardashian's ass. "It's gross," she said. "It reminds me of cottage cheese inside a big trash bag." She now says, "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!" Kardashian has allegedly accepted Paris' apology. "Paris and I have been friends since we were kids," she told In Touch, "and I'm glad she made the effort to say she's sorry." (Photo of Paris and Kim in happier days: Chris Polk/FilmMagic)