Damon is thrilled for his friend, Affleck's, relationship with Lopez.
"Ben and Jen are doing so well and are happier than they have ever been. Ben's in a great place and he really is Jen's biggest fan. He loves being with her and working with her too," the source says.
Damon, the source adds, "loves Jen and thinks she is the best thing that has happened to Ben. Matt is glad Ben is so happy. Things are going great for Ben both career-wise and in his personal life. He feels like he can and will do anything he wants to accomplish in life now that he has Jen backing him and supporting him."
The source elaborates that Affleck and Lopez's relationship has been great for both their individual health and their family's happiness. "He is working out and feels good," the source says. "His kids love him with Jen and like her kids too. They are one big happy family."
Bennifer first got married in July 2022 and then hosted a larger celebration later that summer. This year, the couple is focusing on spending time with the family.
"They are planning some trips together this summer with the kids and hopefully one to two trips on their own so that they can be together just the two of them and relax," the source says. "They both love to stay busy and work, but know it's important to take a step back, enjoy their time as husband and wife, and be well-rounded and healthy. They remind each other of this when one of them is about to book a new project and fills the other one in. It's a way to help them set boundaries and put each other and their family first."
The happy news comes on the tail of Affleck's quips about his early life in Hollywood living with Damon as a roommate.
"Matt's a beautiful guy. I love him. He's my best friend. He's been great to me my whole life. He's a brilliant guy. I would not suggest living with him," he joked during a recent appearance on The Late Late Show With James Corden.
Affleck explained his disclaimer, saying Damon "never paid a bill" and "has an ability to block things out."
"I think that's why he's such a great actor because he can just focus," Affleck continued. "One of the things he blocks out is that when you finish with something, it has to be washed or thrown away."
Affleck added of Damon, who is married to Luciana Barroso, "God bless his wife, Lucy. There's a place for you in heaven."