[stevekemp]

We have had many traditions when it come to relationships - for example the tradition that all couples were a pair of one male, and one female, and they always ended in marriage.

Sure it might be easier to explain your relationship if you're an "average married couple", but there have always been alternatives - even in the past mistresses were common-place, and so were affairs.

I'm married, but I live in a separate house to my wife, for example. That works wonderfully for us, but is obviously not a traditional arrangement - and why should it be?