Britney takes her boys on a playdate...with Gwen Stefani's son

Not content with a famous mother and auntie, Britney Spear’s sons Jayden James and Sean Preston have added another celebrity to their circle – Kingston Rossdale.

The boys were pictured enjoying a playdate with the two-year-old– son of singer Gwen Stefani and Gavin Rossdale - at Spear's home in Los Angeles.

Kingston – who welcomed a younger brother on Thursday when Stefani gave birth to Zuma Nesta - played with the boy's electric car's

while Britney and her mother Lynne Spears looked on.

Celebrity playdate: Kingston Rossdale, left,with a nanny makes friends with Britney's son Jayden James

The singer looked happy and healthy dressed in a black summer dress and flip flops, as she entertained the threesome.

She is currently allowed two visits with Sean, 2, and Jayden, 1, and one overnight per week in the settlement.

Spears officially agreed to give her ex-husband Kevin Federline sole custody last month.

The 26-year-old paid out more than $700,000 (£376,215) in legal fees during the battle.

Two law firms which represented Britney have submitted legal bills into court worth $466,000 (£250,326).

Family fun: Adoring mother Britney reaches out to one-year-old Jayden

That's on top of the $250,000 (£134,358) the 26-year-old pop singer has agreed to pay Federline's attorneys.

The largest bill comes from attorney Stacy D. Phillips, who says in court filings that she is owed nearly $407,000 (£218,716) for four months of work. Phillips claims she has written off another $125,000 in fees.

Attorney Laura Wasser, who took over the case in June and negotiated an agreement between Federline and Spear's camp that allows the singer more time with Sean and Jayden, is seeking $60,000 (£32,246). She worked on the case for nearly two months.

Mother and son: Britney ex-husband Kevin Federline has sole custody of Jayden, 1, pictured, and Sean Preston

Spears and Federline were married in 2004 and completed their divorce last July. She pays him $20,000 a month under an agreement finalised in July.

Phillips claims in court documents the case was made more complicated because Spears is under the temporary conservatorship of her father, James.

He took control of his daughter's personal and financial affairs after a series of high-profile incidents of erratic behavior and two hospitalisations.

Any payments will have to be approved by a Los Angeles court commissioner, and attorneys representing Spears' and her father's interests indicated last week in court they intend to contest Phillips' bill.