Kevin Federline is thinking of going to court to ask for an increase in child support from Britney Spears ... because he never bargained on having the kids full-time when they hashed out the terms of support.
Sources with direct knowledge tell TMZ ... Kevin gets $40k a month for the 2 kids he shares with Britney -- Jayden James and Sean Preston. The amount is predicated on each having the kids 50% of the time. The reality -- Britney has had the kids 0% of the time for years.
Sean Preston turns 18 in a couple of weeks, so the support will end for one of the boys. However, Jayden's will stay intact until around June 2025, when he graduates high school. So realistically, $20k is the relevant amount if Kevin asks for an increase ... but that amount could balloon if he proves he needs more money for 100% of Jayden's care.