Harry and I are just no good at infidelity

Men think that technological progress enables them to sneak around at will, but women are always at least two steps ahead.

Men should realise that mobiles are not freedom enhancing communication tools but tagging devices that record every detail of their lives for their partner's inspection. It won't be long before we start wearing them strapped to our ankles.

Men will protest that women should respect their privacy. But just as men can't hide their misbehaviour, women can't stop snooping for evidence of it. Expecting women not to pry is like expecting them not to worry about their weight. It's what they do.

Even post-feminist types can't stop themselves. I recently dated a thirtysomething who made out she was cool with us being "not exclusive"; but the first time I left her alone at my place, she read my emails and hit the roof at my inclusiveness. Technically, I'd done nothing wrong, but was still made to hang my head and feel like trash.

While women tend to cheat with discretion, such as when abroad, or while laying the groundwork for their next relationship, men leave bigger, slimier trails than a giant slug - because they want to get caught. Men cheat because they have low self-esteem and don't feel they deserve a relationship, or because they want to break up with a woman but don't know how to. It's an act of sabotage that requires unconscious clumsiness and inevitable discovery.

I discussed my latest break-up over dinner with my friends Charlie and Alice. They're soulmates who have been married for 10 years but they tried to make excuses for me. Alice said I needed to be footloose following my divorce, while Charlie tried to comfort me by saying: "Monogamy isn't natural."

I told them that juggling relationships is exhausting, and, however liberated a woman presents herself as being, she'll always want to know where she stands. Monogamy is the sensible option, I said, and they were a great advert for it.

"What's wrong with you?" asked Charlie. "Are you growing up or something?"

Maybe I am. I do know that in my mid-thirties I don't want to be playing the same klutzy games as Prince Harry. Infidelity is a game of stealth. And I, like most men, have no talent for it.