Colin Farrell 'Worried' Over Britney Spears' Book Bombshells, Actor Fears She Will Spill All About Their Short Fling

Britney Spears' upcoming $15 million autobiography has family members and former lovers on edge, RadarOnline.com has exclusively learned. Colin Farrell is "particularly worried" about what his pop star ex-fling may spill within its pages, insiders claimed.

A report claimed the memoir will reveal never-before-shared details about the singer's short-lived romance with Oscar-nominated actor in 2003.

Spears allegedly received a bumper sticker post-split that read, "Honk if you've slept with Colin Farrell," according to The Sun. It was claimed that she has been "wanting to set the record straight for a long time" about what transpired between them.

RadarOnline.com can exclusively report that Farrell is allegedly stressing over her potential toxic barbs in the memoir. Sources said that Spears "raked him over the coals for breaking her heart." Although he apologized for his behavior, the insiders claimed, she's determined to tell her own story, including the peaks and pitfalls.

It was previously reported that her tome's publisher, Simon & Schuster, received "strongly worded legal letters" from those who fear what Spears will share in the upcoming memoir, which has led to its delay. "Britney is brutally honest — there are a lot of nervous A-listers."

Insiders said her book may be just the tip of the iceberg as Hollywood writer Ryan Murphy wants to tell her story in a new TV documentary featuring her own input.

"She would have total control and word is she's mulling over it," the tipster said.

Readers can look forward to a page-turner as Spears' book will be a story "of triumph," Page Six reported. "It will cover her most vulnerable moments, her childhood – being a little girl with big dreams – her breakup with Justin Timberlake, the moment she shaved her head, and her battle with her family over her conservatorship."

Never miss a story — sign up for the RadarOnline.com newsletter to get your daily dose of dope. Daily. Breaking. Celebrity news. All free.

"It is also a story of survival, finding her way out of the crippling conservatorship to finding happiness with her husband Sam Asghari," one publishing source added.

RadarOnline.com has reached out to reps for Farrell and Spears for comment.