Kevin Federline flaunting his new romance with volleyball player Victoria Prince

Britney Spears’ ex-husband Kevin Federline has been flaunting his new romance with volleyball player Victoria Prince all over town in recent weeks. But nothing prepared Britney for finding out that Victoria has also been getting close to her sons, Sean, 3, and Jayden, 2. On Jan. 16, Kevin, Victoria and the boys took a road trip from LA to Clovis, Calif., and then north to the snowy town of Shaver Lake, Calif.

“She was very hands-on with them,” an onlooker tells Life & Style. “She spent a lot of time carrying Jayden in her arms.”

For now, Britney’s team is trying to keep her emotionally stable as she preps for her upcoming tour starting in March. But an insider worries that seeing photos of Victoria with the boys could push Britney over the edge. “Her kids are her life,” the insider explains. “Seeing someone else caring for them like this — holding them, comforting them — will absolutely devastate her.”