Why do men cheat?

John and Marilyn. Bill and Monica. Charles and Camilla. Ashley and Whatshername. The extramarital affair has a long and if not quite distinguished, then at least high-profile, history. More often than not it is the men who occupy that central, adulterous role; difficult as infidelity statistics are to gauge, men repeatedly own up to committing the lion's share of affairs, outnumbering women by at least two-to-one. But why?

That question, age-old as it may be, is not terribly difficult to answer – at least not according to Peadar de Burca – and he should know, having just interviewed almost 300 candidates on the subject.

A playwright, director and comedian, de Burca has spent the best part of six months travelling England and Ireland, interviewing men who have cheated and the women that they have cheated on.

He has spoken to over 250 adulterous husbands, not to mention several dozen of their wives, attempting in each case to identify the motivations, mindsets, and moralities of the unfaithful.

The results have been turned into a two-man comedy show, Why Men Cheat, in which de Burca and his co-star Briane O'Gibne re-enact the tales they have been told, from the small-town soldier falling head-over heels for the leggy women he met on tour, to the big-city banker who got his kicks by setting up swinging sessions around the country.

It's a unusual way to spend time – particularly given that de Burca has not been married that long himself. This, though, was part of his inspiration. "It had been on my mind a lot because there was a history of the males in my family straying," he explains. "I suppose I was a little bit worried about what I might do."

Odd though his subject matter was, it wasn't particularly difficult to delve into. De Burca began with friends and family and worked his way out. Before he knew it, he was booking train tickets left, right and centre, visiting casinos, nightclubs and swingers' groups, and listening to the stories of jilted wives and regretful husbands. "I thought I would maybe talk to 10 or 12 people about it. I would go and hang around with them and get them beers and win their confidence; suddenly they opened up and just started blowing out all these stories. I couldn't stop them."

It wasn't long before a pattern emerged. Throughout his research, de Burca encountered just one instance of what could properly be termed a "love affair". Unlike any other interviewees, the pair in question ended up leaving their spouses and marrying one another. The woman was older, too – more than a decade older than her new husband. It's the exception which, he says, proves the rule. "The men would go for a kind of wife-lite, as it were. The women they would sleep with would look like their wives but be more ... on display."

drive from www.independent.co.uk