Vengeful spouses are said to be turning to post-nups to punish their stray husbands. But there are other reasons why married couple might want to spell out how assets are divided on divorce

For Maria, her husbands infidelity no longer causes her pain, because her retaliation devotes such phenomenal and perpetual delight. She marriage for love but it turned out her husband thought that the life he paid for, the houses, the holidays, the cars and, yes, the yacht was so important to me that he could behave like a rutting stag and Id never leave him, she says. He was speechless when he realised that I genuinely intended to walk away. He went into a sort of decline.

Maria pauses and laughters. His reaction was, shall we say, instead unexpected given how much extra-marital shagging Id detected hed been up to over the years. But it was most useful in helping me plot my course of action.

Maria told her husband shed stay with him on one condition: the couple would open up their pre-nup. Not renegotiate the pre-nup, she tells. This time, it was me doing all the talking.

If her husband strays again, it will cost him dear: the fair divide agreed on before their marriage is now heavily skewed in Marias direction. Its the financial equivalent of castration, she says, calmly. I get so much hell be left with nothing to buy his next floozy.

Maria is flaming a trail: betrayed and vengeful spouses are increasingly turning to the post-nup to punish their straying husbands. Toby Atkinson, a partner in the divorce and family department of Stewarts Law in London, says that he increasingly has clients asking for a post-nup to keep their marriages together. We have had a marked year-on-year rise in terms of the number of clients we have acted for who have entered into post-nups. We are probably doing three to four times as many as we did five years ago.

Just like its older sibling, the pre-nuptial agreement, the post-nup spells out how a couples assets are distributed in the event of divorce or demise. The difference is that a post-nup, as the name suggests, can be undertaken at any time after the wedding has occurred. Like pre-nups, post-nups arent legally binding but they do carry weight in British tribunals, providing they have been signed by both parties without duress and alongside legal advice.

In a 2015 survey by the American Academy of Matrimonial Lawyers, half of divorce lawyers quoth an increase in spouses attempting post-nuptial agreements during the past three years. The tendency has now arrived on our shores, largely is under consideration by wealthy couples struggling to keep their marriages together.

The usual scenario, says Atkinson, is the husband has been unfaithful to his wife and she says to him: I will stay in this wedding, but its going to be on my terms and its going to cost you.

For Ayesha Vardag, signing a post-nup with her husband was a very public festivity of our independence and love for each other.

We signed our post-nup among our friends and family at the reception with great fanfare, having married in Winchester Cathedral, she tells. We wanted to make a statement: we both believe very strongly in couples rights to agree their own affairs as independent individuals , not hand them all over to the country to sort out for them.

Vardag, one of the UKs highest-paid divorce lawyers, says her own post-nup bargains not only with the finances but also with the country in which she and her husband would like the divorce to go through, with confidentiality, social media rules and steps to avoid any ill-will or blame in any divorce petition, despite the fact that English law forces couples to identify which party is at fault. It covers lots of things that we want to agree between us and not leave to opportunity, she says.

German paper company heiress Katrin Radmacher won her pre-nup instance at the supreme court after Nicolas Granatinos divorce settlement was slashed from more than 5m to 1m. Photo: Luke Macgregor/ Reuters

Another reason for the increasing number of post-nups in Britain is the growing number of international ultra high net worth people defined as those with more than $30 m in liquid assets moving to London with their families. The city has become the divorce capital of the world thanks to English laws favourable posture towards the non-wealth-creating spouse usually the spouse and this migration has led to a growing number of extremely high divorce awardings, many in the hundreds of millions. Many wealthy individuals are wising up to the risk and are insisting on formal marital agreements with their spouses before moving here, specifically to protect their assets should their partner issue divorce proceedings, Atkinson adds.

There is another advantage to the richer spouse in having a post-nup, says Sandra Davis, head of Mischon de Reyas family department who specialises in pre- and post-nuptial settlements involving couples with a net worth of between$ 1 million and $30 million. Im negotiating a post-nup at the moment, she says. I find they are often a precursor to divorce where the wealth inventor in the marriage is seeking to get away with paying less than he or she would pay if the matter was to litigate, because, in tribunal, they would have to give full disclosure as to their real worth.

But a post-nup can lead to marital breakdown even if that wasnt the intention. Do I often assure a post-nup lead to divorce? When you set something on the table, you give it legs and then it can walk away by itself. Couples can very quickly fall into arguing when speaking about dividing assets.

Alexei signed a post-nup with his wife of ten years. I am not a buffoon. My spouse is considerably younger than me and, what can I say, I am not perfect, he tells. But I am a very rich man. In Russia, the courts wouldnt make it worth her while for my spouse to leave me. But here its a different story.

Alexei acknowledges he leapt the post-nup on his wife before she knew of his plans to relocate the family to London. I told her that Id been looking at our pre-nup and wanted a new agreement because I loved her and wanted to give her more, he tells. I do love her. But, as I say, I am not a fool.

The impetus to sign a post-nup is not always so soul-destroyingly one-sided. Catherine Costley of the London law firm Payne Hicks Beach, says the post-nup is increasingly use when both members of the couple are earning but decide one partner, likely the mother, is going to give up their career to take care of the children. In cases where one partners earning capacity will have been significantly diminished, a post-nup is a sensible and reasonable act, she says. As a professional female, you wont induce that time back. You cant merely walk back into your high-flying career four, five, 10 years down the line. You wouldnt take a new stance without compensation in your business life, so why do it in your personal life?

Julia, who met her husband when they were both working for a hedge fund, agrees. I actually earned slightly more than him but when children came along we agreed you couldnt have two mothers running the crazy hours we worked, she tells. So I took four years off then went back on a much lower resound of the ladder.

This was a joint decision we made but we were both aware that I was the one taking all the risk, and that wasnt fair. We thought of[ the post-nup] like life insurance. Were still very much in love and very much a couple, but were grown-ups, too, who need to protect most children, and protecting ourselves against worst-case scenarios is the best style of protecting them.

Some names have been changed

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