Is it OK to cheat on your partner when you travel overseas?

There comes a time in most people's lives when they have to admit they've seen the movie Road Trip. For me, that time is now.

Because you mightn't think of this tale of American college kids trying to recover a misplaced sex tape as being one of much philosophical importance, but it did introduce the world to a concept that matches neatly with today's blog topic: the "area code rule". This law, suggested by the intellectual dynamo Sean William Scott, essentially states that if you're in a different area code to your girlfriend or boyfriend and you cheat on them, it doesn't count.

(He goes on to say that if you were too wasted to remember then it also doesn't count, but let's ignore that for now.)

This rule might sound unrealistic in its plausibility, but you'd be surprised how many travellers seem to follow it. Leaving your home has always meant trying new things, acting in a way you might not around your friends and family, taking risks and having adventures – and that attitude can sometimes result in people not exactly being the model boyfriend or girlfriend to their loving partner.

I remember talking about this with some friends a few years ago, and one of the women in our group said she'd never, ever let a guy she was dating go overseas by himself. "He'd cheat, definitely," she said. "That's just what guys do. He'd definitely do it."

That's obviously a bit extreme, but it probably has some small basis in truth. However, while it was comforting for my friend to think of this tendency to stray as a purely male domain, in my experience it's anything but.

I used to work on bus tours of Europe – you know, the kind with lots of fun-seeking Aussies and Kiwis in their late teens and early 20s being carted around the continent's pubs and clubs (sorry, tourist attractions). At the start of each tour we'd get people up to the front of the bus to introduce themselves, and one of the questions they'd answer was whether they were a "red light", an "orange light", or a "green light".

Green if you're single, red if you're in a relationship, orange if you could be swayed in either direction. Time after time you'd see these sweet, sincere passengers get up on the microphone and announce that they were most definitely red lights – then a few days later they'd be emerging from someone else's tent in the morning trying to remember what they'd done with their clothes. This was guys, and it was girls. Usually more of the latter.

The crew always used to say that the difference between a red light and a green light on those tours was about three beers. Three beers and the freedom of Europe on a holiday, surrounded by strangers out for a good time. It happened. A lot. And most of those sweet, sincere passengers then packed up their bags and headed back to their relationship in Australia, their partners none the wiser.