The modern response is for exes to carry on living together, despite their difficulties. This practical "split - what split?" solution keeps the kids (and the bank manager) happy, and prevents tedious arguments over who gets to keep the Charles & Diana tea-towels and the Celine Dion CD, because you both do.
The Duchess of York is at the vanguard of this movement. In 1997, after finding that she was "a bit short", she moved back into Sunningdale Park with her former husband and "bestest" friend, Prince Andrew. Their daughters apparently love the "co-parenting" arrangement. The Duchess explained the mechanics on The Oprah Winfrey Show: "When Papa brings company home for the weekend, the girls and I step down to my father's house. If I want to have boyfriends, then I do it out of the country because it's easier."
Two London architects have tapped into the zeitgeist by designing a "divorced house", for other couples who want to separate but stay together. A prototype, by Cambridge University's Deborah Saunt and David Hills, is up and running in Brixton, and has a separate "duplex" apartment for each parent, and a walkway to allow access between the two areas.
Spice Girl Mel G has apparently come to a similar but more informal arrangement with her husband of eight months, dancer Jimmy Gulzar. When their marriage hit difficulties, they moved into separate wings of their mansion and a "fragile peace" has been restored.
After a disagreement over their son's schooling led to their marriage breaking up, the Labour MP Jeremy Corbyn and his wife Claudia Bracchitta had the same idea; they moved to a new house, divided it into two, and will continue to live together, for the sake of their three sons.
Some exes find that although breaking up is hard to do, staying friendly isn't, and get on ever better after a formal separation. Notting Hill star Julia Roberts is now so close to her former husband, Lyle Lovett, that she hopes he'll give her away if she gets married again. Butch Pearce, from Florida, did just that when his first wife, Sandy, remarried. Although they split up 14 years ago, they remained so friendly that Butch was also the best man at Sandy's recent wedding.
It's a totally practical solution to an age-old problem. But, of course, the real joy of this new trend is that the only people who lose out are the lawyers.