Pop star Britney Spears and Kevin Federline may have divorced, but they still have to share their two children and K-Fed seems eager to play daddy.

Life & Style magazine reports Britney Spears’ assistant, Alli Sims, was served with court papers by Kevin Federline's lawyer early Sunday morning. The lawyer reportedly contacted Sims at a house party, making her “absolutely angry” at the intrusion, the magazine reports.

Alli Sims, who is also Britney’s cousin, spends a lot of the time in the singer’s company. Federline and his lawyer Mark Vincent Kaplan allegedly want to question Sims about Britney’s lifestyle – the partying, the drinking, and her parenting skills.

It was previously reported that Sims was helping her cousin’s ex-husband, in preparation for an upcoming custody trial. She has since denied these reports, insisting Britney is a very good mother.

Britney Spears, 25, and Kevin Federline, 29, are parents to Sean Preston (almost 2 years old) and Jayden James (almost 1 year old). Britney and K-Fed married in 2004 and divorced less than three years later. Their marriage was officially over in July 2007.

Britney has been under public scrutiny for some time now, what with shaving her head in front of paparazzi and entering a rehabilitation center. After leaving rehab, Britney took p dancing classes and even appeared on stage in a series of mini-concerts, performing his from her previous concerts.

While many fans were thrilled to see their idol back on stage, many expressed disappointment over her choice of lip-synching the songs, instead of giving a live performance.

A new studio album is also apparently in the works and has been for some time, according to rumors. Marriage and motherhood took up Britney’s time these past few years – the last studio album she released was “In the Zone,” released in 2003.

Britney is reportedly filming a video for her new album’s first single.