Annet says when she was writing the lyrics she was coming off a fresh split from Britney's musical director ... and the song is mostly about Annet's relationship ... not Britney's unborn child, as some fans now suspect in the wake of Britney's recent bombshell.
Britney had been broken up with Justin for about 9 months at the time, and the song came out after he released "Cry Me a River" ... but Annet says Britney never mentioned a baby or an abortion during the writing process, and neither topic served as inspiration for the track.
Annet tells us she and Britney would sit at the piano together working on the song ... they were friends and were sharing pain, and they were both sad and would play piano together.
As we reported ... the famous lyric that has fans thinking Britney was secretly referencing her abortion is "I guess I need you, baby."
But, Annet says the tagline was just something she wrote about her own experiences with her relationship. To be even clearer, she says it's NOT a reference to an unborn baby.
As for the song's chorus ... "And every time I see you in my dreams I see your face, you're haunting me. I guess I need you, baby" ... Annet says Britney came up with "haunting," though she says they were simply trying to find words with rhymes.
Annet's kind of leaving the door open to the new Britney fan theory though ... she says she was not involved in the music video or the imagery of a woman giving birth, and that was all Britney, so it's possible that visual correlates to the decision she and Justin made to terminate her pregnancy.
Stay tuned ... more conspiracy theories are sure to come.