OK! Exclusive: Britney Loves Her Dog More Than Her Kids!

Brit had her pooch pal London with her during her alleged parking lot incident on Aug.  6. (JFXimages.com)

Last week, beleaguered pop star Britney Spears pulled up to Mexican restaurant Casa Escobar for a strong margarita. But, sources reveal exclusively to OK!, the outing took a less-than-pleasant turn when the "Toxic" singer was told she couldn’t eat with her pet Yorkie pooch, London, in her lap.

“It set her off into hysterics,” the source tells OK! about the scene at the Marina del Rey, Calif., eatery. And a friend of Brit adds, “She cares more about London than her boys! She’ll let anyone hold Preston and Jayden, but has to really trust you for you to even touch London."

The friend also reveals to OK! that, "If one of the boys is crying and London is barking, she’ll pick up London while the nanny calms the babies.”

Unfortunately, not everyone thinks Brit is fit to parent a pet. In fact, animal-rights group PETA hopes her ex-hubby Kevin Federline will also seek custody of Britney’s dog. Spokesman Michael McGraw tells OK!,“ If a court feels she is in no shape to care for her own kids, she certainly shouldn’t be trusted with pets.”

For all the details on Britney's latest oddball behavior, pick up the new issue of OK! — on sale everywhere Thursday.