Britney Spears' parenting skills have been called into question once again, after leaving her two sons in the car to go shopping for chandeliers.Britney Spears' parenting skills have been called into question once again, after leaving her two sons in the car to go shopping for chandeliers.The troubled pop star, 25, was enjoying a monitored day out with her sons Sean Preston, two, and Jayden James, one, on Sunday, as part of the court agreement in her bitter custody battle with ex-husband Kevin Federline.But instead of spending quality time at home with the boys, Spears decided she needed new light fixtures, and stopped off at the Crystal Palace store in Los Angeles - leaving her kids with the court-appointed supervisor.Under the latest court ruling, Spears is allowed to see her two boys three times a week, but must comply with an earlier court order to undergo mandatory drug and alcohol tests as well as attend joint parenting sessions with dancer Federline.The former couple's next custody hearing is set for November 26.It's not the first time Spears has been criticised for her skills as a mother - she almost dropped Sean Preston on one occasion and was seen driving her car while he sat on her lap last year.