COLUMBIA — Three same sex couples plan to go to the Greenville County courthouse this week to ask for marriage licenses.

Alyssa Weaver and Michel McIver, along with the other two couples, know their request will be denied, because in 2006, the state passed a constitutional amendment not just banning gay marriage, but any other type of domestic union.

But Weaver said she wants to call attention to the fundamental unfairness of denying her the ability to marry the woman who in their three years together supported her through breast cancer and has helped her as she goes through nursing school.

“For the three years we’ve been together, we’ve been through a good amount. This totally validated the fact I want to be with her. I want to get married and live with her the rest of my life,” Weaver said last week. “If we can make it through all we’ve been through so far, why can’t we be married and spend the rest of our lives together?”

Weaver and McIver and the other couples are being supported by the Campaign for Southern Equality, which backed about 20 same-sex couples in Asheville, N.C., who also sought marriage licenses knowing they would be denied. But North Carolina has never passed a ban on gay marriage, while South Carolina voters spoke emphatically about the issue.

The amendment defining marriage as only between one man and one woman passed with 78 percent of the vote in South Carolina in 2006. In Greenville County, the amendment received nearly 80 percent support.

When the amendment passed the South Carolina House, just three members voted against it. There was no recorded vote in the Senate.

Weaver and McIver will ask for their license Tuesday afternoon, with two other couples going to the courthouse Wednesday. The couples plan to leave peacefully after their licenses are denied, then hold a prayer service outside the courthouse, where they will ask South Carolinians to change their mind about gay marriage.

“Too many lives have been lost and too many families torn apart because of how divisively this issue is debated in the public square. We do not expect to come to agreement on policy, but we do extend a hand to you, asking you to join us as we pray to our Creator for the strength to always choose love,” the Campaign for Southern Equality wrote in its public invitation for the prayer service.

Weaver should be able to start her nursing career soon, and McIver is almost done getting a master’s degree as she plans a career helping the mentally ill or people with AIDS. They live together in Greenville and have lived in the South most of their lives, but are sad that chapter of their lives will have to come to an end for them to stay together.

“We don’t want to move anywhere else,” Weaver said.

Weaver hopes asking for the license will make people realize same-sex couples have the same hopes and dreams as heterosexual couples.

“Straight people can get married for any reason under the sun,” Weaver said. “While gay couples who have been together for decades are still finding themselves treated as second class citizens.”