Britney's Mom: Kevin Changes Diapers

01/06/2006 at 04:00 PM EST

Kevin Federline is a hands-on dad – literally, according to a new interview with Britney Spears's mother, Lynne.

"Kevin does change diapers," she tells Access Hollywood in an interview scheduled to air Friday.

The Spears matriarch also says she shares a close bond with her 27-year-old son-in-law, who recently released his first music single "PopoZao." "It's very special. I'm very close to Kevin."

Federline is such a committed dad that he skipped a New Year's Eve release party in Las Vegas for his debut single to spend a little quality time with the missus and her friends at the swank W Hotel in L.A., PEOPLE reports in its current issue.

As for the new mom herself, Lynne tells Access that Britney, 24, is "very happy" – and protective of who gets to spend time with 3-month-old Sean Preston.

"She's really picky. She doesn't let just anybody hold him, but she lets me hold him."