Banking, steel, oil, cocaine … Matthew Mellon is heir to a fortune built on the first three, and a victim of the fourth. And although he’s sworn off coke for good, when he wrote a pre-prenup with his fiancé, Noelle Reno, in the form of a business contract, they put in a clause saying that if he ever touched coke (or any similar drug) he would owe her $1 million. In cash.

Why don’t we think of motivators like that when we decide to give up carbs?

Now that the marriage is off, and she is not longer part of Degrees of Freedom, the brand of luxury cashmere knits they established together last year, she brought suit in Manhattan Supreme Court on July 18 to enforce the rest of the agreement. The suit describes what it calls Mellon’s erratic behavior.

They were engaged in Paris, in 2006. The first agreement they signed, in 2007, said she would get $1 million if their home in London was sold.

The drug clause was added in February of this year, in an attempt to protect her financial interests in their design company if he fell off the wagon.

Instead, she walked away from the company and the relationship in June, and she isn’t the first designing woman to decide that Mellon, despite his obvious charms at 43, was too much of a handful.

Her lawyers at Pryor Cashman told “The New York Post,” “Noelle devoted three years of her life to this company and this man and was left with nothing from both.”

The verdict is in. A judge ruled against a wife who broke new ground, and perhaps established new heights in ego-centrism, by broadcasting her complaints about her husband on YouTube. As Norman Sheresky, a Manhattan divorce lawyer, said in April, “It’s the kind of thing judges frown upon.”

Oh yes. Frown they do.

The six-minute video, posted in April, was called “One More Crazy Day in the Life of a Phoenix Rising from the Ashes.” In it, Tricia Walsh-Smith said her husband, Philip Smith, never had sex with her, but kept a stash of Viagra, condoms, and porn.

One complaint, she said, was that her husband tried to curb her habit of buying $600 pairs of shoes on his credit card.

Wearing raccoon eyes and filmed in her lavish Park Avenue apartment, she was hardly doing herself any favors.

The press had a field day: “Her unblinking zombie eyes seemed to mirror some madness in the soul,” said “New York” magazine.

“A wild-eyed Walsh-Smith looks about as sane as Ozzy Osbourne on a three-day coke binge,” said “Wired” magazine.

The judge skipped the invective, but was no less harsh.

“She has attempted to turn the life of her husband into a soap opera by directing, writing, acting in and producing a melodrama,” Judge Harold Beeler said, calling the videos — there were three of them — “a calculated and callous campaign to embarrass and humiliate her husband.”

Smith, 76, head of the Shubert Organization of Broadway theaters in New York, sued Walsh-Smith, 52, for divorce last year, after eight years of marriage, charging her with cruel and inhuman treatment.

Sometimes it pays not to be in a hurry, or at least that’s what a woman’s lawyers are saying in a lawsuit in England. Here’s the backstory. Carol Williams moved out of the family farmhouse in Chesham, after 22 years of marriage and four children.

In November, 2000, she won a divorce from her husband, John Williams, who owned Jencon’s Scientific, the largest supplier of laboratory equipment in the UK.

She said in the divorce papers that she wanted to end a difficult marriage and that her husband was “controlling and overbearing." Her attorneys say she was eager to get on with things, and “make a clean break.”

And clean it was, with a settlement of $2.4 million.

So why is demanding another $2.8 million?

The surprise is that it’s not from her husband. That bird has flown.

She’s demanding it from her lawyers, Thompson Leatherdale of Reading, UK, and Nicholas Francis, Queen’s Counsel, for negligence, for not informing her that the customs of allotting alimony or spousal support were about to change, big time, especially for high net worth couples.

What she said she didn’t know was that a case called White v. White was decided on in the House of Lords in October of 2000. And that case laid down a new philosophy that changed support in the wife’s favor.

Before White v. White, a husband in the UK was expected, after many years of marriage, to pay a reasonable amount for his ex-wife’s upkeep.

Any money he had beyond that was his to keep.

Here's a divorce lab experiment that doesn't work. Mix two celebs with big egos for a toxic brew of parenting no-nos. There was just another court appearance in Los Angeles in the battle between "Two and a Half Men" actor Charlie Sheen and his ex-wife, Denise Richards, who has a new reality show called "Denise Richards: It's Complicated."

Note to Richards: Your behavior is making your life more complicated..

Sheen and Richards married in 2002 and have two daughters, Sam, 4, and Lola, 3. She filed for divorce when she was pregnant with Lola, in 2005.

Their divorce was made final in 2006, but the custody battle has raged on with accusations (dragged through the press) of bizarre emails from her to Sheen, a restraining order against him (he was ordered to stay at least 300 feet from Richards, her home, her car and their daughters, except during supervised visits) and her accusations that he was a gambler, took drugs, and had violent mood swings.

On his side, Sheen had requested that their daughters not appear on her reality show, which premiered on E on Memorial Day. Too late, they are already on it.

And, of course, they battled endlessly over Sheen's visitation rights.

Sheen, 46, got married last month to Brooke Mueller, a real estate investor. Richards said she was happy for him, and had sent a wedding present in their daughters' names.

That rapprochement didn't last long.

Sheen and Richards were in court on July 17, and again yesterday in Los Angeles. Richards asked a judge to restrict Sheen's access to the girls, because "they were having problems." She was said to have a videotape with her that would demonstrate their bad behavior after being with their father, but the videotape was not shown in court.

A custody agreement was reached yesterday allowing Britney Spears to have gradually increased visitation rights with her two sons, while her ex-husband, Kevin Federline, will retain physical custody.

We love hearing when a husband comes to his senses and returns to the loving embrace of his wife and family. Rolling Stone Ronnie Wood was in the news lately for his fling with Ekaterina Ivanova, a 19-year old Russian cocktail waitress.

He had left his wife, Jo, in Britain and jetted off to his home in Ireland with Ivanova.

Friends said he was in the midst of a serious crisis, and his drinking had escalated to consuming two bottles of vodka a day.

Wood has been candid over the years about his struggle with alcoholism, and entered rehab in at least six times before, most recently in 2006.

He had been sober for some time, but relapsed after the end of the last Rolling Stones tour. He met Ivanova in April in an escort bar, and she immediately became a drinking buddy and nude model for him. (Wood is a serious painter.)

One thing is for sure: Ivanova wasn't telling him to reduce his vodka consumption.

Wood's publicist said on July 10: "She is a drinking partner. When you're an alcoholic and your family are all telling you to stop drinking, you simply find someone else to drink with. You can see how it happens, you end up pushing away the ones you love because you don't think straight."

What got him back to his senses? Seems like his oldest son, Jesse, 30, was able to remind him of what he would lose if he left the family nest.

Page Six reported that Jesse "flew to his side and convinced him to return home and get help."

According to the BCC, Wood entered rehab yesterday.

Wood, 61, married Jo, 53, in 1985, and have two children, Leah, 29, who got married earlier this month (Wood is pictured with Jo at the wedding), and Tyrone, 24.

Here’s a new way for the ex-basketball player Jason Caffey to keep score: ten children by seven “baby mamas” and one wife. He filed for bankruptcy last August. That didn’t stop a judge in Atlanta, Georgia, from handing down a ruling on Wednesday that Caffey, because he didn’t show up in court, owed one of them, Lorunda Brown, $17,088.87 in legal fees.

The judge dismissed Caffey’s motion “with prejudice.” That ain’t good.

It was a response to Caffey’s failure to turn up in court on his own motion to modify child support to Brown.

Caffey was a professional basketball player in the NBA until 2002. When he filed for bankruptcy last fall, his papers stated he owed $1.9 million, mostly in long overdue child support.

He said he made $11,500 a month from – get this – a string of daycare centers and a sportsbar in Alabama.

He also listed assets of two NBA championship rings (worth $10,000) and a 2006 Dodge Charger (worth $34,000).

His problem, his lawyers said, was that his expenses are $15,000 a month. Thus, he is bankrupt.

His wife, mother of two of his children, filed for divorce last year.

Coincidence?

Bankruptcy does not cancel child support obligations, but it does put a hold on collections until the person filing for bankruptcy sets up a payment plan.

That tripped up another Caffey baby mama, Karen Russell, in April. Russell is baby mama No. 1, having given birth to a son 15 years ago. (She and Caffey met at the University of Alabama.)

Caffey began missing child support payments in, ahem, 1995, she says.

He did, however, make regular payments, when the child support was deducted from his NBA salary, which ran as high as $5 million a season.

(And wouldn’t we like to see those pay stubbs? That must have been a way for him to remember all of the baby mamas’ names.)

In filing for divorce last week, Cynthia Rodriguez, wife of Yankee Alex Rodriguez, seems to be expecting more than just the house, their two daughters, and the four dogs. Since they married in 2002 her husband signed a contract for $275 million in 2007; he is rumored to be worth somewhere around $400 million. And despite their prenuptial agreement, she hopes to get some.

Florida does not consider fault in granting a divorce, but it does consider fault in alloting child custody and support.

And just to be prepared that no accusations of fault are thrown at her, Cynthia Rodriguez has asked to see any dirt her husband has on her, which is to say, any reports from wiretapping, videotaping or private detectives. At least she’s asking to see those materials in a long list submitted to the court last week.

Any woman facing divorce from a wealthy man, even if she has a prenuptial agreement, might make note of these requests.

Cynthia Rodriguez's lawyers asked for:

A “long form” financial statement

Pay stubs, check stubs and registers

Bank statements and broker statements

Stock, bond, and mutual fund certificates

Stock options

Deferred compensation agreements

Wills, powers of attorney, and life insurance policies

A list of outstanding debts

Cash receipts

All deeds and tax bills

Homestead exemption receipts and mortgages

Sale agreements on any property

List of personal property

Firearms registrations

Invoices and appraisals for all motor vehicles

Any records of corporate interests

Partnership and joint venture agreements

Contracts for any consulting jobs, projects, speeches, etc.

Records of all fringe benefits

Business records of partnerships

Lists of all charge accounts

All memberships cards or documents

Gifts of any kind received during the course of the marriage

Medical bills

After losing joint custody of his kids, losing any thread of dignity, losing potential clients (since women are the ones who often make decisions on hiring architects), Peter Cook had a revelation.

He told Fox News last night that, if he had to do it all over again, when he met future paramour Diana Bianchi, he'd say, "No, I'm a married man. Move on."

There is one problem with this revelation. It was he who was pursuing Bianchi, an 18-year-old girl. It wasn't as though she was pursuing him.

He was an adult married man who should have known better, just like Bill Clinton should have known better when he tangoed with Monica Lewinsky.

That's why we can't blame a Monica Lewinsky or a Diana Bianchi as much as we should blame their married lovers.

Yes, it takes two to do the horizontal mambo, and even young girls should have the moral backbone to dance away from this entanglement.

But in both cases, it was the mature adult who was in the power position and had the influence to sway what happened.

In life, there are consequences for whatever you do, as well as the opportunity to learn from them.

Mothers out there should remind their lovely, nubile daughters that these trysts with married men — despite the intoxicating halo of power around them — often have horrible outcomes.

Affairs destroy families and reputations. Rarely does the young woman get a long-term relationship with the husband, or even a soon-to-be-divorced man.

In fact, a Kinnsey Institute study of 2,000 people found that only 17 percent of males who had affairs were planning on leaving their spouses. And only 9 percent of the men planned to marry their current lovers.

Note that Peter Cook's current girlfriend is Suzanne Shaw, a 36-year-old single mother, not the now-21-year-old Diana Bianchi.

Another lesson is that most wives are not like Bambi in the headlights, in total shock and surprise over the affair.