Kevin Federline cheated, claims ex-girlfriend

Actress Shar Jackson says she and Kevin Federline were still together when he and Britney Spears began dating last year.

Jackson, then pregnant with her second child with Federline, says the truth came out only after he flew abroad for a commercial - which became a months-long trip with Spears.

"How do you call yourself a human being knowing that you put somebody else through that pain?" Jackson asked.

Federline has a daughter, Kori, and a son, Kaleb, with Jackson.

She and Federline "are still really good friends," Jackson says. "All I want from Kevin is his time with his children."