Summer Phoenix, wife of “Manchester by the Sea” Oscar-winner Casey Affleck, filed for divorce Monday, 16 months after their representative announced they were separating.

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E! News said Tuesday that Phoenix, 38, younger sister of actor Joaquin Phoenix, cited irreconcilable differences and requested joint physical and legal custody of their sons — Indiana, 13, and Atticus, 9 — as well as spousal support. The two had married in June 2006.

Affleck, who turns 42 on Aug. 12, is the younger brother of film star Ben Affleck. In addition to his Best Actor Academy Award, he was nominated for Supporting Actor for 2007’s “The Assassination of Jesse James by the Coward Robert Ford.” Neither the couple nor their representative have commented publicly.