Robert De Niro, one of our favorite actors, and his wife Grace Hightower, the philanthropist and singer, have quietly parted ways after more than two decades together. They have experienced quite a few highs and lows over the course of their 21-year marriage. De Niro and Hightower married in 1997 after dating for nearly a decade, and they have two young kids together. But this is not the first time the couple has broken up. The pair called it quits in 1999, before reuniting and renewing their vows in 2004. This week, a source close to the family confirmed that De Niro and Hightower have separated and are living apart.