Philanthropic billionaire playboy Stewart Rahr may regret not signing a prenup, as he could pay up to $800 million to his divorce-seeking wife of 43 years.

Mr. Rahr allegedly did not want to get a divorce because it would cost too much, but he did not sign a prenuptial agreement.

Now his wife Carol may be entitled to half of his $1.6 billion fortune, which would be New York’s biggest divorce payouts of all-time.

“Stewart always said he’d never get divorced because it would be too expensive,” a source told the New York Post. “They met when he didn’t have two cents to rub together. She could be entitled to half his $1.6 billion fortune.”

Carol Rahr‘s decision to file for divorce came after the couple had been living separately in recent years.

According to Forbes, Mr. Rahr is estimated to be worth $1.6 billion after the sale of his pharmaceutical company, Kinray, to Cardinal Health for $1.3 billion in November 2010.

In addition to the actual money, assets including the couple’s $43 million home in the Hamptons and their Trump Park Avenue apartment are up for grabs.

Rahr has donated over $25 million to charities since selling his company.

We will not label Mrs. Rahr as a gold-digger, as she married him before he accumulated his wealth. 43 years more than qualifies as a legitimate marriage.

James Gilbert | Elite.