In 2007, their partnership was announced with the superlative nonsense typical of the luxury goods industry. Tiffany, the world's most famous jeweller, and Swatch, the maker of Omega and other fine Swiss watches, had "married" to make a range of "timepieces" including "a horological jewel with a curvaceous silhouette and a shower of diamonds that would have caught the eye of Audrey Hepburn in Breakfast at Tiffany's".
But now the pair are at daggers drawn over the total collapse of the relationship. Swatch sued first, seeking damages of Sfr3.8bn (£2.7bn) and declaring the partnership at an end. Tiffany had been too slow to make decisions and did not even display the £2,500-a-pop watches at its store on Fifth Avenue in Manhattan, it said.
Yesterday was Tiffany's turn, countersuing for Sfr541.9m amid claims that it was the injured party.
Swatch had vigorously rebutted the suit by lunchtime.
Some analysts have said the deal's collapse could weaken Tiffany and make it a bid target. That might be going too far, but we should expect a costly divorce for all sides.