Outraging his entire family, O.J. SIMPSON including KHLOE KARDASHIAN in his multimillion-dollar will, say sources.

“O.J. believes Khloe is his natural-born daughter through his affair with Kris Jenner when she was married to his buddy Robert Kardashian – and he wants to do something about it,” revealed an insider. “At 65, he’s tired and becoming increasingly aware he may not ever leave prison alive. He says he wants to ‘do the right thing.’”

But surprisingly, the disgraced football star also wants to cut his oldest daughter Arnelle out of the will after accus­ing her of squandering his money on booze, parties, lavish vacations and shopping. But all of his kids – four from two marriages – are enraged by his sudden decision to change his will and refuse to speak or write to him as he rots in a Nevada prison cell on armed robbery and kidnapping charges. While he becomes eligible for parole in 2017, he could also wind up serving the full 33 years of his sentence.

Despite his legal woes, O.J. is sitting on top of a fortune, The ENQUIRER has learned.

Although he’s been crying poor mouth, Simpson has actually stashed away more than $2 million in secret Cayman Islands bank accounts – and he has millions more coming to him over the years through his NFL pension.

Now O.J. wants to make sure Khloe gets part of it. She was born after his 1983 affair with Kris and, as The ENQUIRER has re­ported, he’s become convinced that she is his daughter.

But when he told his four children – Arnelle, 43, Jason, 42, Sydney, 26, and Justin, 24 – he was including Khloe in his will, all hell broke loose.

“At first they thought he was just making a big joke, but when they realized he was serious, they were flabbergasted,” said the source. “They are furious and wonder why they have to share the wealth with a complete stranger.”

Simpson added insult to injury by dis­inheriting Arnelle. As The ENQUIRER previously reported, he complained that her alleged mishandling of his money led to the impending foreclosure of his four-bedroom Miami-area home.

“He blames Arnelle for not paying the mortgage and blowing the bulk of his monthly NFL pension checks on lavish living,” said the source.

“When OJ told Arnelle he wanted to include Khloe in his will for an equal share of his estate, she got angry. That just made him even more furious and he told her point-blank he was cut­ting her out of his will. He said she’s already gotten her share and has spent it.

“While O.J. paid Justin and Sydney liv­ing expenses out of his monthly pension payments of $25,000, most of it went to Arnelle, and he says she just wasted it.

“Now he’s cut off Arnelle except for a small allowance.”

Simpson’s NFL pension pays him $300,000 a year. That money cannot be touched by the Gold­man family, which won a civil suit against him following the murder of their son Ron, who was brutally slain alongside O.J.’s second wife Nicole Brown in 1994.

The pension money, minus his expenses, will be held for him until he goes free. And it could wind up being millions by then!

In another bombshell, sources revealed to The ENQUIRER that O.J. has secretly stashed away a pile of loot from a book con­tract and memorabilia merchandise. Although his planned fictional account of Nicole’s murder, “If I Did It,” was eventually published by the Gold­man family, not O.J., he boasted to friends that he got about $1.8 mil­lion in advance money. “He said he sheltered a cool million of it in Cayman Islands accounts,” said the close source.

O.J. made another fortune signing various sports memora­bilia – raking in at least $1 million from 1995 through 2007, added the insider.

“He had memorabilia snuck in and out of his jail, even back when he was awaiting trial for Nicole’s murder,” the insider explained. “He told me he was hiding the profits offshore.”

And that money can easily be protected from the Goldman fam­ily, according to a financial expert in offshore banking.

“It’s a very simple legal process,” the expert told The ENQUIRER.

But his kids remain furious at their high-handed father.

“They think he is a real jerk for taking out everything on Ar­nelle, who uprooted her life in Los Ange­les to move to Florida to take care of him,” said another source. “By cutting Arnelle out of his will, his kids feel O.J. is being cruel. And they think that adding Khloe is just plain revenge. I’m sure if O.J. kicks the bucket and leaves Khloe money in his will, she’s not going to turn it down