Britney Spears News

Sources close to Britney Spears' estranged ex tell E! News that the "America's Most Hated" rapper has refused to sign off on divorce papers because he is concerned for the well-being of their two children amid reports that the rehabbed Spears has been making the nightlife scene.

"It's not about the money," the source said of Federline's refusal to sign on the dotted line. "It's about her partying. It's her partying ways that is forcing Kevin to put his foot down."

His balking keeps the couple legally bound, despite both parties having reached a "global divorce settlement on all issues of their marriage," including custody of their sons, in March.

Under the terms of the agreement, Spears and Federline would continue to share joint legal and physical custody of Sean Preston and Jayden James, with the majority of the children's week spent with Spears.

However, Fresno's finest rapper now wants to revise the divorce document to make it possible for him to minimize Spears' access to the kids should she again bottom out to head-shaving proportions of self-destruction.

A source reiterated that Federline will seek new custody orders based on his concerns that Spears is failing to abide by assurances she made after leaving rehab, when Federline agreed to the terms of joint custody.

Any claims that Federline wants more money is "without merit," the source says, adding that his primary focus is "protecting his children."

There was no comment from Federline's lawyer, Mark Vincent Kaplan. (Kaplan has also been tapped to work his litigious magic on Pamela Bach's divorce from David Hasselhoff and Skating with Celebrities' Lloyd Eisler.)

Spears and her reps are also remaning mum on the Federline front as she seems to be taking care of one problematic relation at a time.

The comeback-minded popster made quite a show of handing over some kind of document to her mother, Lynne, Thursday.

The delivery was dutifully chronicled by paparazzi, but no one is saying definitively what was in the missive.

Some reports have pegged the mystery paper as a restraining order seeking to limit Lynne Spears' interaction with her grandchildren. Mother and daughter have had a rocky relationship since Britney entered rehab (the younger Spears apparently blames her mother for forcing the issue).

"It was a love letter," Lynne Spears told an X17 cameraman of the document handed over by her daughter. "She did not serve me."

It must have been an important love letter—the former pop star drove roughly 30 miles to Valencia to deliver it to her mom, who was accompanying her other daughter, Jamie Lynn, to the set of her Nickelodeon show, Zoey 101.

Another photo agency, Splash News, reports that Spears made the journey out to Valencia only after conferring with paparazzi camped outside her own home. The "Toxic" singer asked the photographers if they knew the whereabouts of her mother and sister.

Meanwhile, TMZ reports the mail call was actually a letter from an out-of-state lawyer requesting that Lynne keep away from the Federline boys should she be on any medications that would impair her grandmotherly judgment.