Ben Affleck’s Relationship with Ex Lindsay Shookus Was ‘Good’ But ‘Complicated,’ Says Source

Ben Affleck and Lindsay Shookus had a strong bond despite their breakup, a source tells PEOPLE.

“When it was good it was really really good. When they were in the same time zone and not focused on other things it was good,” the source says. “It became incredibly complicated with their families, with their jobs.”

Although the actor, 46, and the Saturday Night Live producer, 38, recently split after over one year of dating, the source says Affleck enjoyed how much Shookus challenged him.

“He really liked her. He loved that she was smart, funny, opinionated,” the source adds. “When they were together it brought him a bit outside of his comfort zone. She brought a bit of fresh air into his life that he needed.”

WATCH: Despite Drama, Ben Affleck Relationship Was ‘Worth Risking A Lot’ For Lindsay Shookus: Source

Another source close to the former couple told PEOPLE that Shookus ended their relationship after she couldn’t handle his struggles with addiction anymore.

“Lindsay had been supporting Ben’s sobriety and going to meetings with him. She had him in meditation and they were doing it together,” the source said. “His recovery was something that was very important to both of them.”

As Affleck began to spiral in recent months, however, Shookus felt increasingly helpless, said the source. In the end, she decided it would be in Affleck’s best interest to end the relationship. Affleck checked into rehab last week.

“It was very hard for her to break up with Ben, but she knew he wasn’t getting better and that it was time for her to step aside,” the source said.

Affleck — who was seen recently spending time with 22-year-old Playboymodel Shauna Sexton — entered rehab on Wednesday. His ex, Jennifer Garner, 46, drove him to a Malibu treatment center.

Affleck’s first time in rehab was in 2001. In March 2017, he announced that he had completed treatment for alcohol addiction a second time.

If you or someone you know is in need of help, please contact the SAMHSA substance abuse helpline at 1-800-662-HELP.