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 monthslong trip with Spears.
Federline and Spears were wed last year; their son was born in September.
"How do you call yourself a human being knowing that you put somebody else through that pain?" Jackson asks of Spears in the December issue of Sister 2 Sister magazine. "That's a vicious cycle right there, man. We gotta break that."
Jackson, 29, and Federline have a 3-year-old daughter, Kori, and a son, Kaleb, born in July 2004. Jackson, who co-starred in the TV series "Moesha," has two older children from a previous relationship.
She and Federline "are still really good friends," Jackson says, but she doesn't want child support.
"Hell no. I am a very, very independent woman, OK? If I wanted child support that's an easy procedure," she tells the magazine.
Instead, "All I want from Kevin is his time with his children. That's it, bottom line."
Jackson is working on an album, her first. A track from Federline's debut recently appeared on the Internet.