"Ben felt she wasn't supporting him and vice versa. His friends have tried to advise him that he has to support her, but Jen feels he left her hanging."
And with tensions rising, the source claims, it seems Affleck, 42, has thrown in the towel.
"He hasn't gone back to her to try to fix her hurt feelings,” the source said. "Like, he just doesn't care. Ben doesn't want drama so he hasn't confronted her.”
Meanwhile, Garner has moved to Montreal for the summer to film her next movie, Nine Lives, and the children are likely to join her.
And according to an insider, it's an arrangement that could become permanent. In an event of a divorce, said the source, "Jen's going to try for full custody."