On Wednesday, Sexton, 22, showed off her abs and wore a simple necklace for her sandy outing.
“He is happy being able to date who he wants and not feel tied down to a serious relationship,” a source told PEOPLE.
PEOPLE confirmed Affleck has entered rehab for alcohol addiction on Wednesday night with a source saying, “He is seeking treatment. He knew he needed help and was vocal about it.”
A second source tells PEOPLE in this week’s issue Garner’s focus remains on their children.
“Is she happy about him hanging out with a very young Playboy model? Certainly not,” the source tells PEOPLE. “But her concern right now is not who he is dating. What she ultimately cares about is his sobriety and whether she can rely on him to co-parent.”