Ah, but Catholics do not base all of their beliefs on the text, even the NT. They also base their beliefs on tradition and authority. That is the strongest argument doctrinally against gay marriage (and women priests and various other things.)

Yeah, I said in my previous comment that I think it's silly not to be checking out the couples for other mortal sins. It's not particularly clear why couples have to conform to this aspect of Catholic belief but not others. I would be a lot more sympathetic to their position if they wanted only to place children with committed Catholic couples.