On Nov. 30 Britney Spears and her husband, Kevin Federline, had such a heated argument that, a source close to the couple tells PEOPLE in its latest issue, Spears dropped the D-word, and Federline bolted from their Malibu home.
"She wanted a divorce," says a friend of Spears's. And, says a source close to Federline, "when she's upset with him, he likes to give her some space. I don't think she's upset with him because of something specific he's done. I think she's overwhelmed with her new lifestyle – being a wife and mother – and sometimes takes it out on the people who she's closest to and who she knows will stick around."
Of course, Federline, 27, didn't seem too tortured during his own marathon of clubbing in Vegas a few days later: First he and his all-male entourage hit Pure Nightclub, where he caught up with Nicole Richie's fiancé, DJ AM, then partied at the club Tao Las Vegas until 4 a.m.
In any case, the punishment proved short-lived. After her 24th birthday on Dec. 2, Spears took a quick jaunt to Vegas (where she checked into the Wynn Las Vegas resort, half a mile down the Strip from her husband's suite at the Venetian), then repaired to Louisiana to spend time with her mother, Lynne, and sister Jamie Lynn.
But by Tuesday, according to a source close to the couple, she had settled back into her Malibu mansion with her husband and their 3-month-old son Sean Preston. "This has happened before," says an insider. "They always work it out."
For more on Britney and Kevin, pick up the latest issue of PEOPLE, on newsstands Friday.