The 30-year-old singer-actress recently announced her engagement to boyfriend Eric Johnson, who she has been dating for seven months, just days after her ex-husband Nick Lachey announced his plans to marry again.
According to Popeater.com, Simpson and Johnson – who only finalised his divorce from his wife of five years just last month – will not be signing a prenup, despite the Dukes Of Hazzard star being worth an estimated $100m.
But the news has not gone down well with Simpson’s father Joe, who is reportedly biding his time before he steps in to protect his famous daughter's fortune.
A source told the site: 'At the moment, Joe is sitting back and being a great father, supporting his daughter and his future son-in-law.
'However, you can bet after all the excitement has died down, Joe is going to do everything in his power to make sure Jessica doesn't walk down the aisle until Eric signs away any right he might have to Jessica's enormous fortune.'