"I have had to explain to people who joined the business recently that we are going through a divorce because sometimes Mark and I are perhaps more familiar with each other - he'll say to me: "That idea is crap," whereas with a colleague we'd couch things in better terms. If you've been through the worst of times with someone you know everything and that really helps in a business environment."
When Louisa Scott, 44, and Jez John, 47, separated in 2006 after ten years of marriage, the decision to keep running their two growing business together - digital agency Webstars and music publishing company Make My Day - was the simple bit.
"We'd talked about separating for about a year before we finally did, but because we loved each other we were always trying to find ways around it," says Louisa. "I suppose in some ways the continuity of working together was one of the easiest aspects."
"Splitting the businesses down the middle would have been incredibly difficult and probably caused both to fail," adds Jez, who believes it was more awkward for their staff than it was for them. "We were a much smaller company and it was a very tight-knit team. One of the hardest parts was telling clients we were no longer together."
Since their divorce came through in 2010, the former couple can see only upsides. "We no longer fall into the trap of assuming we know what the other one is thinking which, in the early days, we were guilty of," says Louisa. "And we no longer have the sense of loyalty that you have to agree with something because you are married. We get on better as colleagues now, but also because we have that shared history."
Anne Brichto, 53, feels similarly. She first met husband Derek, 61, working in a local bookshop over 30 years ago, and they went on to open a bookshop together, which they still run, despite separating five years ago.
"Not working together was not even a consideration after we split up," says Anne. "We have such different skills that I think we'd go bankrupt without each other. Derek is good at the everyday graft, making sure the bills are paid and he's got a great eye for spotting books. He's the anchor and I'm the innovator - the starting engine. A business needs both. I can't imagine working without him."
Their working relationship has improved dramatically since they split. "Before we separated it was really hard on our staff - one of us would say one thing, the other another. If we had staff meetings one of us would talk and the other would cut across and interrupt, as husbands and wives do. Now we have some distance, I really value what he's good at and see him in a new light.
"I really underestimated his qualities and we let each other play to our strengths a lot more."
Derek is on the same page: "When you are spending 365 days a year living, sleeping and working together it can be a big strain. Most couples can separate for eight hours a day while they go to work but Anne and I never had that. Now that we've separated and live apart it's made a huge difference - we are not grinding each other down, and because of that we are working so much better together, the business is doing better."
Redefining your relationship is key if you want to work together after splitting up, says relationship coach Susan Quilliam. She advises working out who will be in charge of different areas of the business, and agreeing to support each other's decisions. Leaving behind bad feelings is also crucial. "If you divorce and you intend to keep working together, the main thing to concentrate on is moving to a point of neutrality. That means either leaving something in the past or forgiving it. I'd also advise keeping your personal life even more separate than you would do in a normal working situation - it's not a good idea to come bounding in saying you've met someone else."
Mark, 53, agrees: "When Cathy and I first split up I did think I couldn't carry on working together. But as time has gone on it's got easier. There has been some adjustment, of course; but we still have a strong connection and a great respect for each other about what we do. I don't feel there is a tension any more."In fact, the tricky thing is not Cathy and I working together - it's our new partners not understanding how we can be just professionally involved."