There are 33 ways to dispel a mistress according to one of China's top love detectives. An unusual new industry has taken hold in some of the country's top cities. It's called "mistress-dispelling", and it involves hired operatives doing what it takes to separate cheating husbands from their mistresses. With the surge in super-affluent families in China, there has also been an apparent upsurge in the number of men choosing to keep a concubine. And for wives who see divorce as a humiliating option, almost no expense is sometimes spared in seeing off the rival. For Crossing Continents, Ed Butler meets some of these private detectives and "marriage counsellors", heads off on a mistress "stake-out", and asks whether this is all a symptom of a deeper crisis in gender relations in China.

Reported and produced by Ed Butler.