Simon Cowell
Simon Cowell has been blasted by Alexander Silverman, the brother of his pregnant lover's husband, for 'unbelievable betrayal'.

Simon Cowell has been accused of adultery in divorce papers filed by his friend Andrew Silverman, after it emerged his wife was having the media mogul's baby.

According to reports, Cowell has been named as a co-respondent by the cuckolded real-estate tycoon who filed for a 'fault-divorce based on adultery' against his wife Lauren, despite New York being a no-fault divorce state.

The move, widely regarded as a means to disgrace his wife, means that Cowell, 53, could be called to the witness stand to reveal his finances, as well as details of the affair with the mother of his unborn child.

"It's really a signal to the spouse who cheated that the wronged spouse is very angry and that it's going to be a very nasty, scorched-earth, high-profile litigation," divorce attorney Martha Cohen Stine told the New York Post.

Lauren Silverman is believed to be "around 10 weeks along", with the baby due mid-February. She already has a nine-year-old son with her current husband.

The 36-year-old brunette allegedly plans to leave her estranged husband to be with the X Factor impresario.

Silverman's furious brother has expressed his disgust over the baby news and branded the pregnancy a breach of trust by Cowell.

Alexander Silverman told the New York Post: "It is an unbelievable story of betrayal. It is a sad story and a tragic story."

It has been suggested that Silverman was 'so oblivious' to Lauren and Cowell's affair that he recently upgraded his wife's engagement ring with a 10-karat diamond, according to a friend.

"She's a total gold-digger. The pregnancy was by design," a source told the New York Post.

But another insider claimed that the writing was on the wall for months.

A source told Us Weekly: "Lauren and Andrew have been unhappy in their marriage for some time, and their divorce has been in the works for a while."

"As their marriage deteriorated, she and Simon became closer," the undisclosed source added.