As poor Cheryl Cole prepares to do battle against husband Ashley in the divorce courts for what some claim will be a hard-fought settlement worth £20m, one imagines the likes of John Terry and Vernon Kay can only pray that their own recent transgressions don't reach a similarly ugly conclusion. But as Divorce Confidential, an unashamedly lurid memoir from top US lawyer Gerald Nissenbaum, suggests, whenever the wealthy separate, things can get very messy indeed.
"I would say half our cases end quickly and amicably," he suggests, citing one in which a husband and wife with $70m between them happily walked away with $35m each. And the other half? He smiles sagely. "Well, the other half don't."
This should not, of course, be particularly surprising. Whenever there are broken hearts involved, the ensuing fallout rarely brings out the best in people. And if it is not money they are fighting over, it's the children.
"Every parent who has ever pushed for custody insists he or she is doing it out of love," he writes in the book. "Hate is more like it." Divorce is never pretty, he goes on, but custody fights define ugly. "Parents throw everything they have at the other side, the more disgusting, horrendous and despicable, the better."
If, as Nissenbaum says, a divorce lawyer plays as crucial a role in the modern marriage as the vicar, then Nissenbaum and his type are people many of us will come to rely upon at some stage in our lives, whether we like it or not. It is a profession necessarily mired in misery, jealousy and anger. Nevertheless, he loves it.
"The divorce court is not just where I make my living, it's my playground!" he booms. "It's exciting, it's fun." Fun? "Absolutely! It has to be. Listen, if I didn't laugh at some of the silliness these people do to one another, or the outrage, I'd have ridden my high horse straight into an institution by now."
He gives an example. (Nissenbaum has a great many; his book is filled with them.) It's the tale of a woman whose husband was in the process of transgendering. "When he first met her, he would get dressed up [in women's clothes] for things like Halloween. She thought this was fine at first, but then over the next decade he dressed up more and more, he started going to certain clubs, and then came out and said he wanted a sex change." It was at this point that the woman wanted a divorce. "I asked her, why now? And she said to me, Well, if I am going to be married to a woman, it won't be him."
He laughs out loud. Such mordant humour, he insists, is as necessary in his line of work as a permanently fired-up legal mind. Nissenbaum has both.
A lawyer for more than 40 years, Gerald Nissenbaum switched from criminal law to divorce at the end of the 1960s after he grew tired of working for the mob. Born and raised in gang-heavy Boston, he gravitated towards his speciality essentially because divorce was, back then, a growth area, and an increasingly profitable one at that. Now 70, he commands upwards of $700 an hour for his time, his client list almost exclusively rich beyond reason.
Sat in his well-appointed office in downtown Boston on an early March morning, he is far more amiable in person than he appears in print, a genial, avuncular man who wears his age lightly and displays a penchant for the kind of bow ties one would expect more on a children's entertainer (he favours them in all the colours of the paint palette). In the book, however, he is thoroughly hard-boiled – a tirelessly wisecracking character straight out of 1950s pulp fiction who spends his life dealing with duplicitous women who find imaginative ways of impregnating themselves in pursuit of alimony, and a great many violent men. During his career, he has worked on custody fights, kidnapping plots, prostitution and extortion; the one enduring constant of so many of his clients is that when love is gone, only hate remains. "And hate," he grins, "is a great way of expressing how you really feel about somebody."
His role, then, is a necessary one. "I help stabilise a bad situation," he insists. "I help money start to flow, I enable visitation rights to get going. My aim is to improve things for people when they need it the most. As a divorce lawyer, you get to see people at their very worst. It's fascinating."
Perhaps unsurprisingly, he is an avowed advocate of divorce.
"Hey, sometimes it is the only solution," he says, adding that this is virtually imperative when children are involved, and all ameliorative alternatives have been already, unsuccessfully, sought. "Oftentimes, it is the kids that know long before the parents do that there is going to be one, or else that there should be one." In a bad marriage, he points out, it is the children who suffer most. "For a child to continually wake up to arguments every day isn't easy. They become fearful of their own home, and so school becomes a refuge for them, the only safe place they have. And what do they do at the end of the day? If they go home, it is to more arguments. So instead, they hang out on the street corners, where they can get into trouble. That's wrong."
But what takes up the majority of his time these days are the finer points of the premarital agreement, or the so-called "prenup", in which primarily celebrities and the uber-rich attempt to safeguard themselves in the all-too-likely event that their love will one day die – at which point, as the Bible doesn't say but perhaps should, one shall invariably seek to fleece the other.
"There are only two types of people who can afford to divorce," he says. "The poor, because they have nothing much to lose in the first place, and the rich, because they have everything."
Though one would expect a prenup to rather kill the whole romantic notion of a marriage, Nissenbaum insists that the couple that agrees on one is a wise one. Divorce, he points out, is a part of modern life. "Forty per cent of marriages end in divorce," he says. "That's the reality. When Paul McCartney was going through his with Heather Mills, everyone in the United States said, Why didn't he have one? They couldn't believe it."
The reason he didn't, Nissenbaum explains, is that prenups didn't yet exist in the UK. This may change in the near future, however, as the House of Lords is currently deciding whether or not such a thing is now necessary. Its existence would have certainly saved the former Beatle an awful lot of unpleasantness.
"The way I understand it," Nissenbaum says, "Paul had been offering Heather somewhere between £25-35m to settle, but that she wanted so much more, and that her demands for more were so great that ... well, that there was simply no way to settle [she was eventually awarded £24.3m]."
Which rather bears out the frequent accusation at the time of Heather Mills, that she was motivated by pure greed.
"I think that is the adjective that would apply, yes," he says carefully.
For someone who has spent his professional life watching the personal lives of others unravel, Nissenbaum has managed mostly to avoid such unpleasantness himself. Not entirely, though: his first marriage foundered after 18 years ("we were young") but he has been married to his second wife, also a lawyer, for 29 years. They have three children together, and when they were growing up, he turned one of the rooms in their shared office into a crèche in order to minimise the disruption work can so frequently have on family life. This is something he now extends to his associates when they become parents themselves, which makes him, he suggests with a broad smile, "Terrific to work for!"
It would be more than his job's worth for him to wish such equilibrium upon everyone, of course, because that would mean no need for divorce lawyers at all. And so it is to his clear advantage that marital harmony remains so frequently impossible to maintain. After four decades of seeing this happen, he must have learned plenty about the human condition?
"I have, yes," he says. "I have learned that we have a way to go yet. As humans, we need to evolve more, I think."
Divorce Confidential by Gerald Nissenbaum is published by Ebury, £11.99.