As his 40th birthday nears, Kevin Federline dished on his plans to mark the occasion. The 39-year-old DJ revealed that he will ring in the day on March 21 with sons Preston and Jayden. He shares his sons with ex-wife Britney Spears. He said the birthday agenda consists of a "family thing at the house.” He said the "low-key" plans make everything "easier." Federline also has two daughters with his new wife Victoria Prince. Peyton and Jordan will also join in on the fun.