Britney Spears' ex-husband is to seek an increase in child support payments from the singer.
The 'Toxic' hitmaker - who makes a reported $475,000 a show from her Las Vegas residency - currently pays Kevin Federline $20,000-a-month for their sons Sean Preston, 12, and 11-year-old Jayden, an agreement based on a percentage of her income at the time, but the dancer's lawyer, Mark Vincent Kaplan, sent a letter to the 36-year-old star last week asking to open up discussions regarding the payment.
A source told E! News: "Kevin is trying to voluntarily revisit a modification of the existing child support number, given that the kids are older and the financial circumstances of the parties are significantly different than when the child support was originally resolved.
"A letter asking to meet and confer on the issue was sent to Britney's representative on Thursday."
According to The Blast, the letter didn't specify how much Kevin is looking for, but he wants a "big increase".
However, the 39-year-old DJ isn't looking for a nasty public battle and hopes they can resolve the matter through private discussions.
Kevin - who was married to Britney 2004 to 2007 - wants his child support based on how much custody he has with his sons and also how much money the 'Piece of Me' singer earns, to ensure the boys can live an equal lifestyle with both parents.
Last summer, Kevin - who also has children Kori, 15, and Kaleb, 13, with ex-fiancee Shar Jackson, and Jordan, six, and Peyton, three, with wife Victoria Prince - admitted co-parenting with his former partners has grown "a lot easier" now as they have an established routine in place.
He said: "You fall into your routine and it's really easy now. It wasn't always easy, but it's a lot easier now."