No mother-in-law sleepovers. Only one football game per Sunday. Mandatory sexual positions. With celebrity marriages often shorter than Jessica Simpson's Daisy Dukes, the power of the prenuptial agreement cannot be denied.

Simpson and soon-to-be-ex-husband Nick Lachey didn't have a prenup — he actually had more earning power than she did when they got married three years ago — so Simpson could have to part with half of the $30 million she earned last year. That's a lot of Chicken of the Sea.

Other recent breakups include Valerie Bertinelli and Eddie Van Halen and Christina Applegate and Jonathon Schaech. Prenups are the norm for most stars — even regular folks should have one, if you listen to Kanye West — and these documents can dictate far more than who gets what. Attorneys say some recent celebrity prenups include:

• Limiting the wife's weight to 120 pounds or she must relinquish $100,000 of her separate property.

• Allowing a spouse to perform random drug tests, with financial penalties for positive results.

• Requiring a husband to pay $10,000 each time he is rude to his wife's parents.

• The previously mentioned rules regarding mothers-in-law, football and sex.

"Everything is legal unless you're dealing with custody of children or child support," said Los Angeles divorce attorney Robert Nachshin, who has represented Barry Bonds (his ex signed the prenup the day before their wedding) and author Terry McMillan (who discovered the young hubby who brought her groove back was gay). "Everything else is up for grabs."

So if Simpson had planned ahead, she could have limited Lachey's football-watching plus protected her "Dukes of Hazzard" and Dessert cosmetics dollars.

"People have their own little peculiar peccadilloes they're concerned about," said attorney Leon F. Bennett, who has represented Marlon Brando, Kelsey Grammer and Dennis Hopper. "People of wealth have a sense they have power over others that their money can acquire, and reality shows it can."

High-profile prenups typically contain confidentiality clauses to keep them out of the public eye, Nachshin said. Even during divorce, many celebrities keep their arrangements private by hiring a retired judge to oversee the proceedings, said attorney Connolly Oyler, who has represented producer Sam Simon and Ali Landry.

Infidelity clauses are common, Nachshin said. Michael Douglas agreed to pay Catherine Zeta-Jones millions should he stray, and Denise Richards made similar requirements of Charlie Sheen.

Custody of pets is another common concern. Bennett once handled a case that dictated the destination of a couple's taxidermied horse. Even gardeners, baby sitters and pool men have been addressed.

Most states, including California, consider anything earned or bought after the wedding day to be community property that should be divided equally in a divorce. Prenuptial agreements — which are signed by both parties by don't have to be filed in court — can legally determine the distribution of almost anything the couple shared, from art collections to country club memberships.

But discussing the prenup isn't exactly romantic.

"The problem is the implied distrust," said Jeremy Ritzlin, a longtime Los Angeles marriage and family therapist.

One of Bennett's celebrity clients was so worried about offending his future wife, he skipped a prenup in favor of financial planning to keep his pre-marriage property separate. Roseanne Barr was so in love with Tom Arnold before their 1990 wedding that she fired her attorney for suggesting she sign a prenup. When the couple divorced four years later, Arnold left with $50 million.

Britney Spears was reportedly so taken with Kevin Federline that she refused to sign a prenup until her mom and business managers intervened.

"They may be blinded by love and lust," Bennett said, "but they still need to be protected."