Brian To / WENN 1 / 4
Brian To / WENN 1 / 4

Casey Affleck and Summer Phoenix have decided to call it quits after nearly 10 years of marriage.

"Casey and Summer have amicably separated. They remain very close friends," Affleck's rep told ET on Wednesday.

Affleck, 40, and Phoenix, 37, have two sons together -- 11-year-old Indiana and 8-year-old Atticus -- and have been married since June 2006. Affleck is close friends with Phoenix's older brother, actor Joaquin Phoenix, whom he collaborated with on 2010's controversial "I'm Still Here."

Interestingly enough, Affleck's older brother, Ben Affleck, also split with his ex, Jennifer Garner, last June at the 10-year mark of their marriage.

These days, the Batman v Superman: Dawn of Justice star says he's "on great terms" with Garner. "Jen's great. She's a great person," the two-time Oscar winner recently told The New York Times. "We're on great terms. I just saw her this morning, so that's the reality that I live in."

Affleck also said he had no issue with Garner's much talked-about tell-all with Vanity Fair last month, in which she opened up about the dissolution of their marriage.

"She felt like she wanted to discuss it and get it out there and get it over with, so she could say, 'Look, I already talked about it -- I don't want to do it again,'" Affleck shared. "It's fine. She's allowed to talk about it."