The 52-year-old actor - who has three children, Violet, 19, Seraphina, 16, and Samuel, 13, with his first wife Jennifer Garner - separated from second wife Lopez, 55, in April 2024, after two years of marriage.
Lopez has 17-year-old twins Max and Emme - who she has with her ex-husband Marc Anthony - and her children and his own kids joined him at the Los Angeles premiere of his new action film The Accountant 2 on Wednesday night.
Speaking on the red carpet, Affleck took a moment to praise J.Lo for maintaining a wonderful relationship with his kids, despite their split.
Speaking to Entertainment Tonight, he said: "For the record, Jennifer Lopez is spectacular, great to my kids, great ongoing relationship with them.
"I love her kids. They're wonderful. She's (an) enormously important, tremendous person of a lot of integrity who I adore and am grateful to.
"I'm thrilled that the kids are here with me.
"The relationships that you can have with children like that, it's the joy of my life.
"And those kids are amazing, and I'm glad that this is a movie they want to come to."
Affleck also admitted that he avoids reading anything about what people think of his relationship with Lopez, because he doesn't want negativity in his life.
He said: "I don't read the stuff online much, and sometimes I get the sense that people perpetuate this idea of … they want to find something negative to talk about."
The Accountant 2 - which follows forensic accountant Christian Wolff who "teams up with his estranged but highly lethal brother to track down mysterious assassins" - is something the star is "proud" of , and the night was even more special knowing that his and Lopez's children were there to support him.
Affleck - who told GQ magazine in March 2025 that there is "no scandal, no soap opera, no intrigue" surrounding his break-up from Lopez - said: "It's a great night. The kids are here, Jen's kids are here. I'm very, very excited.
"I'm proud of the movie, I love the movie, and I love when all the kids come out.
"It's really fun, it's exciting."