The 27-year-old's LP has yet to be released, but a track called Y'ALL AIN'T READY has appeared on the internet.
Federline celebrates the lifestyle he shares with Spears and their baby son Sean Preston, but makes an embarrassing slip - confusing the word paparazzi with the surname of opera singer Luciano Pavarotti.
He raps, "Back then they called me K-Fed/ But you can call me Daddy instead.
"Go ahead and say whatcha wanna/I'm gonna sell about 2 mil, oh, then I'm a goner.
"I know you all wish you was in my position/Cause I keep getting' in situations that you wish you was in, cousin.
"Steppin' in this game and y'all ain't got a clue. Getting anxious? Go take a peep/ I'm starrin' in your magazines now every day and week.
"But maybe baby you can wait and see/ Until then all these Pavarottis followin' me."