The face of marriage in Scotland, England and Wales changed dramatically in 2014 with the introduction of same sex marriage.
Since then, same sex couples have had the option of entering either a civil partnership or marriage.
Whilst the change was welcomed by many as bringing equality for same sex couples, others were concerned that it would result in inequality for heterosexual couples who cannot enter into a civil partnership.
That same year, it was reported that a London-based heterosexual couple filed a judicial review at the High Court in London as they felt that they were being discriminated against based on their gender and sexual orientation by virtue of them not being allowed to enter into a civil partnership.
Whilst the couple can marry, it has been reported that they feel that it is a patriarchal institution, arguing that in a democratic society any social institution should be open to all.
By not allowing them to enter into a civil partnership, they claim that this is incompatible with their human rights and is discrimination.
Earlier this week, the court hearing got underway at the High Court in London, and the decision is awaited with great interest - watch this space...