The duo met before the two co-starred in the '90s hit "Cruel Intentions" and married shortly after filming wrapped.
Phillippe, 40, told HuffPost Live that the former couple reminisced recently about the film on a day when the exes decided to get together with the kids in New York.
"She was just here doing press ... and we got to meet up as a family and take a walk through Central Park with the kids," he said. "We shot a lot of 'Cruel Intentions' [in Central Park]. We were there with Ava and Deacon, and they were tripping out about the fact that we were there shooting a movie before they were even a thought in our minds."
Have his kids seen "Cruel Intentions"?
"They haven't seen much of my work," he said. "I guess Ava could, but I've only done one or two non-R-rated movies."
As for co-parenting, Phillippe said it couldn't be going any better.
"It's a feeling out process and I think we've gotten to a really great place," he said. "She's happy and remarried and our kids are incredible. I'm proud of the way we've handled it and who our little people are."