Celebrity Breakups of 2011: Ashton Kutcher and Demi Moore, J.Lo and Marc Anthony, and More

After four years -- that's forever in Hollywood! -- Paris Hilton's younger sister Nicky, 28, and her main squeeze David Katzenberg announced they were calling it quits in July. Unlike most Tinseltown breakups, however, they "remain close friends," an insider told Us Weekly.

After four years -- that's forever in Hollywood! -- Paris Hilton's younger sister Nicky, 28, and her main squeeze David Katzenberg announced they were calling it quits in July. Unlike most Tinseltown breakups, however, they "remain close friends," an insider told Us Weekly.