Posted Jan. 29, 2009

Is it a détente, or a new round of discord for Britney Spears and Kevin Federline?

According to People, the exes are doing their best to be cordial, with K-Fed receiving an impromptu invitation from Brit's decision-making dad, Jamie, on Sunday to join a family barbecue they were having at her new Calabasas, Calif., estate.

Federline, who we suspect has never turned down an offer of free grilled meat, reportedly arrived at the house around noon to pick up sons Sean Preston, 3, and Jayden James, 2, from their weekend visit with their mom. The trio ended up leaving about 5 p.m. and headed home.

The next day, however, relations between the former flames seemingly soured in a big way.

K-Fed and Victoria are spotted together in Los Angeles on Jan. 22. (©X17Online.com) More photos of K-Fed

The Chicago Sun-Times says they had an unpleasant phone exchange that centered on Kevin's budding relationship with onetime volleyball player Victoria Prince, who has recently been photographed toting around Sean and Jayden.

A spy tells the paper it was less a conversation than a "total hysterical screaming match," during which the tour-bound but still road-to-recovery-walking popster purportedly referred to Prince using the nastiest of all female-centric four-letter words as she expressed how she didn't want her "anywhere near my kids."

Federline, who has full custody of the tykes, allegedly responded, "You really don't have much say about that."

Kevin and Victoria, who play in the same bowling league (the Party Animals, if you were wondering), were first spotted smooching in December, and they recently enjoyed a weekend getaway with the boys.

Spears "hates the thought of this woman mothering her sons," a snitch tells OK!. "She's afraid she's going to take her place. And it's tearing her up inside."

Still, the Sun-Times source is able to squeeze some lemonade out of this alleged lemon-filled chat with Federline.

"Unlike in [other emotional episodes in] the past, Britney didn't go take a pill or a drink, but went downstairs and did some yoga to calm down," relays the insider. "I think that's a good sign she's growing up and dealing with Kevin's b.s."

(©BritneySpears.com) More photos of Brit

Another good sign: her oh-so-impressive cheese-grating abs.

Britney's Web site has released several new photos of her busting a move in a surprisingly stationary bikini top as she rehearses for her "Circus" tour, which launches in New Orleans on March 3.