"There was nothing to split from as it has been casual," a friend of Affleck's told the magazine.
The reported split comes a few days after Affleck and the Playboy Playmate were spotted on a romantic Montana getaway, where Sexton posted a snap of Affleck on her social media for the first time.
"He enjoyed being with her but is working on himself, and being together with her at this time is not something that works," the source added. "He will date in the future, but now his focus is on his sobriety, family and his next project."
The two started dating before he checked into rehab for alcohol addiction on Aug. 22 earlier this summer; during his stay, Sexton was spotted driving his SUV and even visiting him at the treatment center. Shortly after he completed his stint, they went on vacation together.
Affleck opened up about his 40-day stay in rehab last week, releasing a lengthy statement via his Instagram.
"This week I completed a forty day stay at a treatment center for alcohol addiction and remain in outpatient care," Affleck's statement began. "The support I have received from my family, colleagues and fans means more to me than I can say. It's given me the strength and support to speak about my illness with others."
"Battling any addiction is a lifelong and difficult struggle," he continued. "Because of that, one is never really in or out of treatment. It is a full-time commitment. I am fighting for myself and my family."
"So many people have reached out on social media and spoken about their own journeys with addiction. To those people, I want to say thank you," he said. "Your strength is inspiring and is supporting me in ways I didn't think was possible. It helps to know I am not alone. As I've had to remind myself, if you have a problem, getting help is a sign of courage, not weakness or failure."
"With acceptance and humility, I continue to avail myself with the help of so many people and I am grateful to all those who are there for me," he concluded. "I hope down the road I can offer an example to others who are struggling."
Shortly after he exited rehab, his divorce with Jennifer Garner was finalized three years after they initially separated. They started dating in 2004 and married in 2005. They share three children: 12-year-old Violet, 9-year-old Seraphina and 6-year-old Samuel.1comments