Kevin Federline, Britney's Dad Jamie Spears -- Time Heals All

They were once locked in a battle royale ... but now Britney Spears' daddy Jamie Spears and ex-hubby Kevin Federline are acting like best buds.

Remember when K-Fed wrestled custody away from a then-unstable Britney? Well now they split time with Jayden James and Sean Preston, and at a youth soccer game this weekend in Woodland Hills, everything seems hunky-dory.