Still, since the couple split in 2007, Federline says, raising their two kids, Sean, 9, and Jayden, 8, has been "great."
"Co-parenting is going great, I can't complain," he told Access Hollywood Monday. "We talk when we need to and it's always about the boys, mostly school stuff and making sure we stay on top of that. It's just, it's going great."
He also gave an example of how it works.
"I had to work this weekend and go to Orange County [California], my DJ thing," he said. "So, they went to Vegas, [to be with Spears] ... and when she has to go do something, I pick up the kids. It just works well."
Indeed, he said he opened his DJ set in Orange County with a Spears' song. "People relate me to her so much," he said. "It's kind of like an ice breaker for the club."
Federline, 36, has six kids in all, two with his current wife, Victoria Prince.
"I'm in a happy place right now," he added, also reflecting on his time with Spears. "That time. It's like a whirlwind. You're thrown into this limelight and everything kind of happened. It was a good time in my life."