Breaking up is hard to do for any couple — but with Sean Penn and his actress wife of 13 years, Robin Wright Penn, the saying especially holds true. The blond beauty filed for divorce from the Milk star in Marin County, Calif., on August 12, citing "irreconcilable differences." The Hollywood pair, who seemed to be together as recently as May, initiated a split twice prior to the latest court action, but withdrew papers both times. “I have no regrets. I, we, have two amazing children we raised together,” Robin said in an interview released on August 17. The proud parents expressed their wish to share custody of 16-year-old Hopper, and also have an 18-year-old daughter, college-bound Dylan.