Canberra mapSame-sex couples began to marry in Australia on Saturday, but those marriages may not last more than a week.

The Australian Capital Territory that includes the capital city Canberra legalized same-sex marriage. The federal government is challenging the law.

The High Court is scheduled to rule on the legality of the law on Dec. 12. Even if the court allows the marriages to stand, the Parliament could then pass legislation making the marriages illegal. The current prime minister was elected on an anti-marriage platform.

Despite that, couples traveled from around the country to the capital to marry.

One of the arguments against same-sex marriage is one that hasn’t been used by opponents in the U.S. and is one of the most logical. They argue that making marriage legal in one state and not others is confusing.

Opponents in Parliament argue that same-sex marriage will mean same-sex parenting that will involve taking a child from its biological parents to give to same-sex couples.

“Same-sex marriage means same-sex parenting,” said Australian Christian Lobby spokesman Lyle Shelton. “That means necessarily taking a child from its biological mother or father and giving it to someone else.”

They don’t explain why those perfect heterosexual parents will be losing or giving up their children just so same-sex couples can be parents.

A marriage equality bill came up twice in Parliament last year but didn’t pass.