Sandra Bullock is reportedly reluctant to divorce Jesse James

The Oscar-winning actress - who has been left devastated by allegations the motorcycle enthusiast cheated on her with at least four other women - has allegedly told friends their almost five-year marriage is over but is scared to call in the lawyers as she`s worried he will get his revenge.

A source said: "The main reason Sandra has not filed divorce papers yet is because she doesn`t want to trigger Jesse into attacking her publicly and revealing her secrets.

"Sandra is one of the most private actresses in Hollywood. And the last thing she wants is Jesse out there talking about her and talking about her marriage. She`s been worried that if she drops divorce papers on him now he`ll want revenge and will try to harm her reputation.

"His behaviour is so erratic that she doesn`t want to send him over the edge."

Jesse - who has publicly apologised to his wife and admitted he deserves "everything bad" which may come from his "bad judgement" - is currently in rehab receiving treatment for sex addiction but is keen to save their marriage.

However, Sandra, 45, has ignored his pleas although she wants to avoid a nasty public divorce.

The source added to RadarOnline.com: "Sandra is a very private person and always has been. She keeps a close group of friends that keep her secrets. She doesn`t want an angry ex-husband revealing things she wants to keep private.

"During the past several weeks she`s had several phone calls with Jesse and he`s pleaded with her to stay married. But he`s also grown angry when she wouldn`t agree. And that`s what has her worried and has frozen her into inaction.

"She believes that Jesse would be so angry by divorce papers that he would destroy the privacy she`s fought so hard to maintain."

sections: Celebrities