networkn: I think I'll pass on what I consider the definition of marriage debate with you, but thanks for the offer.

Fair enough. I will just say however that the definition of Marriage differs greatly between cultures and has changed significantly over the last 100 years, and ever more so over longer periods of time.

In most western cultures, the one man + one women element of marriage (and it is just one element) has been pretty unchanged for a long time. My view (and I realise this is an opinion and others differ) is that many aspects of marriage have changed and evolved over time, and history suggests that changes that increase equality do not seem to interfere with the marriages of others, and don't correlate to any negative effects on the concept of marriage.

Have you by chance got a degree in Anthropology or History?