Smitten Cameron Diaz is putting her $90 million fortune at risk – by NOT asking fiancé Benji Madden to sign a prenup!

The Hollywood hottie, 42, started dating the tattooed “Good Charlotte” singer, 35, in May, and worried pals tell The National ENQUIRER that she’s letting love cloud her better judgment.

“It’s totally insane, but Cameron’s so crazy in love right now no one can get through to her,” a longtime pal told The ENQUIRER.

“Even Benji thinks they should have an agreement. But lovestruck Cameron can’t think of anything less romantic than signing a legal document outlining the terms of a 

Benji’s $14 million fortune pales in comparison to Cameron’s wealth, and the “Sex Tape” star’s business team is desperate for her to get this prenup to protect herself, a close friend said.

“But Cameron’s banned the subject from even being mentioned in her presence,” said the insider.

“She’s a romantic and a flower child at heart. She really thinks the prenup is a surefire way to jinx their relationship.”

It would be the first marriage for both, and while they’ve yet to announce their engagement, the “Charlie’s Angels” actress has been spotted wearing a huge diamond engagement ring all over Hollywood. Their close friends say the couple will tie the knot next May.

Despite all the good feelings, friends think Cameron is blinded by love.

“Cameron loves Benji more than any money in the world,” an inside source said.

“She really thinks they’ve got a shot at ‘happily ever after.’

“But everyone’s worried she could be making the biggest mistake of her life!”