Judgment is due later in two landmark legal challenges against Northern Ireland's ban on gay marriage.
Mr Justice O'Hara will rule on two separate cases that were heard together due to the similarities of the arguments.
In the first case, two couples in civil partnerships - Grainne Close and Shannon Sickles and Chris and Henry Flanagan-Kane - argued the region's prohibition on same sex marriage breached their human rights.
Both couples were, respectively, the first and second in the UK to enter into a civil partnership after Northern Ireland became the first part of the UK to make that option available in December 2005.
They took a case against Stormont's Department of Finance and Personnel, which regulates the region's marriage laws, on grounds that the ban contravenes entitlements to marriage and a family life under the European Convention on Human Rights.
Stormont's Attorney General John Larkin also argued against the legal challenge.
In the second case - known as Petition X due an anonymity order - two men who married in England in 2014 are attempting to get their union recognised in Northern Ireland. Their marriage was changed to a civil partnership in law when they moved to Northern Ireland.
Their solicitor, Ciaran Moynagh, said a successful challenge would result in the first ever recognition of a same sex marriage in Northern Ireland
"This couple took their vows because they believe in the traditional values associated with marriage," he said.
"They see it as the ultimate sign of commitment and best foundation for a family. That's why having it downgraded to a civil partnership has been so distressing."
The judgments come amid a long-running political dispute on the same-sex marriage ban in the region.
Northern Ireland is the only part of the UK and Ireland where a prohibition still exists.
A majority of Assembly members backed a law change the last time the issue came to the floor of Stormont, but the socially conservative Democratic Unionists triggered a contentious voting mechanism to effectively block the measure.
Powersharing has since collapsed and the gay marriage issue is one of the sticking points preventing its restoration, with Sinn Fein demanding the DUP stop standing in the way of a change.
The DUP insists it is not homophobic and is only defending the "traditional" definition of marriage.