Guiliana Rancic
Giuliana Rancic's book Going Off Script talks about her 'crazy childhood', dealing with cancer and her on-screen rejections from George ClooneyReuters

Giuliana Rancic has opened up about her past relationship with actor Jerry O'Connell, stating that he cheated on her with two women during their year-long relationship over a decade ago.

In her new tell-all autobiography, Going Off Script, the widely recognised E! anchor explains that the pair had a shaky romance between 2003 and 2004 and reveals that he cheated on her with former Spice Girl, Geri Halliwell.

When Rancic called out the actor about his affair, she says his response was merely "Yeah, I know. I'm so sorry. I don't know what happened." She later describes in her book that "he had as much emotion as the customer-service representative who tells you your bags missed the flight."

It wasn't just the 41-year-old's reply to the confrontation that annoyed Rancic however, but the idea that she "was being two-timed for one of the lesser Spices". It has not been confirmed as to whether Halliwell knew O'Connell was in a relationship at the time of their alleged involvement.

The Fashion Police regular also states in her self-written memoir that O'Connell strayed from their relationship with Rebecca Romijn, who he first met at a Maxim's 100 Hottest Women party back in 2004. In an excerpt from Going Off Script, Rancic pens: "Little did I know he was in the VIP area, talking up Rebecca. As a prelude to feeling up Rebecca."

The pair finally split when, tired of O'Connell growing distant, Rancic decided to confront him about everything. But her determination (and their relationship) was short-lived after that, as he allegedly would not let her in his apartment and told her, "Sorry, homegirl... Things change, but you take care, OK?"

The Sliders star went on to marry X-Men actress Romijn in 2007 and the couple are still together.

Meanwhile, Rancic has been linked with entrepreneur husband Bill Rancic since 2004, after first meeting him during an interview discussing his win on Donald Trump's television programme, The Apprentice.

The extremely public pair wed in 2007 and became part of a reality television show broadcasting their marriage two years later. Giuliana & Bill aired its seventh season last year and will likely return for an eighth some time in 2015.

Singer Halliwell is also in a long-term relationship and is set to marry her fiancé Christian Horner in May. The ex-girl band member and the Red Bull Racing Formula 1 boss met in 2009 but only started dating each another in March 2014.

Going Off Script is available in the US as of today (7 April) and is scheduled for UK release on 4 July.