Co-parenting may seem easy for some celebs but for others its always an issue. Its been recently reported that Nas has claimed that Kelis has violated the terms of their custodial agreement for keeping their son over passover. It is said that is has become such a mess that their own lawyers have verbally assaulted each other in the courtroom. TMZ reports. Nas is reportedly asking the judge to hold Kelis accountable for her actions. However, Kelis has defended herself by saying that their eight-year-old son, Knight, wanted to be with her during the holiday. Those claims are yet to be proven.He's asking for $22,000 for all the lawyers' bills he's had to pay when she's allegedly violated their custody agreement.