If only it were really Britney's song.
"Fed-Up" is an angry missive dedicated, it would appear, to her soon-to-be ex-husband:
"Think that you can walk all over me/And you think that I'll just let you be/Now we're going to do things differently/Cause now I see, now it's clear to me," the song begins over a dance beat.
"When I met you I was so naïve/Didn't see what you were, in love you see/Right now I suggest you get your things and leave/Your time is up here with me, I'm fed up."
It sounds like Britney. It looks like Britney. If only it were Britney.
"That is NOT her vocal, that is NOT a song on her forthcoming album," Britney's representative, Gina Orr of Jive Records, told FOXNews.com by e-mail.
Spears, who has two sons with Federline, is currently in the studio working on her album, slated for release in the second half of 2007, Orr said.
The faux "Fed" song explains Britney's initial attraction to the former backup dancer in the chorus.
"I know we all get crazy/Everyone makes mistakes/But there's only so much baby I'm willing to take," she croons. "And if you push me too far, that's when I'll push you back.
"So out of my house, out of my life, off my back."
In the second verse, the as-yet-to-be-identified singer talks about driving around wearing nothing but panties. Spears made headlines in the fall for appearing pantyless on several occasions in Hollywood with Paris Hilton.
"Sneaking pictures of me, I don't care, catch me driving in my underwear, smiling at ya as I pass you there," the pseudo-Britney sings.
Britney's 2004 hit "Toxic" recalled her falling under the spell of a dangerous man; the faux "Fed-Up" song proclaims a return to sensibility.
"Feel like I have finally woken up, it's been so long," the girl sings in the chorus. "The spell that I was under has worn off. I'm moving on."
While many of the postings were of the "you go girl" variety, a few fan postings on YouTube.com doubted that the song was actually Britney.
"It is very possible that this is NOT a real Britney track," one listener wrote. "The vocal is overproduced/filtered to its bits, so it could've been recorded by any female vocalist. Or even a male one. But I like the song anyway."
The "Fed-Up" track comes as Federline announced he would appear in a Super Bowl advertisement parodying himself.