Britney Spears and Paris Hilton

Paris Hilton and Britney Spears who struck up an unlikely kinship in late November 2006, following Spears’ separation from hubby Kevin Federline, had to call their friendship off after the media backlash.

“Britney called Paris and said she had decided not to be seen in public with her ‘for now,’” a Hilton source tells Us.

Though the pair were once practically joined at the hip (they previously had a sleepover in Las Vegas and were spied dancing on banquettes at West Hollywood’s Hyde), things went sour after Spears took heat in the media for partying while leaving her two kids, Sean, 15 months, and Jayden, 3 months, at home.

“Britney told Paris that it’s not personal,” says an insider.

But beware a Hilton scorned. According to another source, the heiress, 25, didn’t invite Spears to her December 18 Christmas party and now refers to her ex-pal as “Animal.” Why?

“Britney doesn’t think about things before she does them. She just acts out,” says the source.