From Henry VIII and Anne Boleyn to Alex Reid and Chantelle Houghton, the issue of who can marry whom always strikes a raw nerve.
The changing boundaries of the institution of marriage and what role it should hold in society cuts across a number of issues, including legal rights, morality and religious belief and competing ideas of tradition.
In that light, it isn't surprising that the joint proposal by Sinn Fein and the Green party to allow gay marriage provoked some forthright exchanges both in the Assembly and in the media.
The Assembly voted down the proposal, but the rather fraught debate around the issue has obscured the straightforward legal facts and few people will be any the wiser as to whether any change would have had an impact on the rights of gay, or straight, couples in Northern Ireland.
This motion would have addressed something technical rather than legal: the issue of definition, rather than a change to existing practice. Currently in Northern Ireland, the legal protections offered by the Civil Partnership (NI) Act 2004 dealing with wills, tax allowances and pension rights are the same as those offered by marriage.
In spite of the defeat of this proposal, those important safeguards for gay and lesbian couples across Northern Ireland will still be in place; providing peace of mind and an important legal backstop.
Opponents of gay marriage are correct to say that there is currently no difference between a civil partnership and a marriage in respect of rights in a divorce, or the dissolution of a civil partnership. In those cases, the two different types of arrangement are treated equally.
They are, however, incorrect to say that the two are totally equal. A change in definition may not have impacted on divorce laws, but there could potentially have been ramifications in terms of children's laws and, in particular, the rights of a gay and lesbian couple to foster, or adopt, a child.
Earlier this year, the Northern Ireland Human Rights Commission failed in its attempt to overturn a ban in Northern Ireland's adoption legislation that prevents gay and unmarried couples adopting children - a practice which is already allowed in England, Scotland and Wales.
Any change would have posed difficult questions with the way the adoption law is currently framed - as it would, in effect, have created a 'two-tier' marriage system.
It's important to be clear that this motion would have had no impact on the ability of religious institutions to define their own 'appropriate' criteria for marriage. All that would have changed would have been the ability of the state to recognise such relationships.
Incidentally, that would have brought the position of the Government into line with what it already offers non-religious straight couples. Civil ceremonies, which require no religious element, are already offered by councils across Northern Ireland.
It is ironic that Northern Ireland - which led the way in 2005 by being the first part of the UK to allow civil partnerships - is now lagging behind the rest.
The SNP in Scotland has indicated that it will be bringing a Bill forward to address the issue of gay marriage and David Cameron has previously indicated his support for the movement in England and Wales.
Some commentators have seen this vote as putting the issue to bed. However, the civil partnership laws are relatively new and there will undoubtedly be challenges to the status quo in the coming years - not least in the area of adoption laws and, perhaps, straight couples seeking to have their relationship recognised as a 'civil partnership', rather than a marriage.
We might not have to wait for a seven-year itch before the Assembly has to revisit these arrangements.