Kevin Federline is asking for more monthly monetary support from ex-wife Britney Spears for their two sons now that she is making tons of money.

Child Support

Federline's attorney Mark Vincent Kaplan has sent a legal letter to Spears' team asking the pop star to revisit child support agreements. Currently, Federline receives $20,000 a month in child support for the couple's sons Sean, 12, and Jayden, 11.

This amount was agreed at the time when Spears was not actively working or making enough money because she was battling serious mental health issues. The amount was based on a percentage of her income at the time.

However, Spears has made a massive comeback in recent years from her Las Vegas residency and the former backup dancer wants to bank in on her success. According to reports, the "Toxic" singer earned $475,000 per show, which added around $15 million to her bank account.

Federline wants his ex-wife to increase the monthly child support for the sake of their kids. He wants them to "live an equally opulent lifestyle with each parent." He also believes that he has done his part in being supportive of his ex-wife during the highs and lows of her career.

He has made sure that she sees their sons often and has always made it his priority to accommodate her schedule. He reportedly even travels to her shows just so she could be with the kids. Federline believes that the success in Spears' Las Vegas residency was in part because her kids have been in her life.

"Kevin has always been supportive of Britney's recovery and has always recognized what a great mother she has been," a source tells US Weekly.

 "Britney's entire world are the boys, period. She just lights up when she is with them," the source adds.

Legal Custody

Jayden and Sean live with their father, who remarried in 2013 and shares two children with his wife Victoria. Spears, who was married to Federline from 2004 to 2007, lost sole legal and physical custody of her sons in 2008 because of her much-publicized breakdown. She was then placed under the care of her father, Jaime, in a still-ongoing conservatorship.

Federline did not state in the letter how much he wants from Spears but it is clear that he wants a big increase. He is also hoping that he can revisit the child support discussions without involving the court and wants it done privately.