As more and more gay couples are doing these days, Michael Galbreth and Jack Massing will don tuxes on Saturday and walk down a wedding aisle to say their vows. But what will distinguish their marriage from ones happening in Iowa and most New England states isn’t just the fact that it will have no legal standing in Texas, which confers none of the rights and responsibilities of marriage to same-sex couples, even if they’ve been together as long as Galbreth and Massing, who celebrated their 25th anniversary last year. Or the likelihood that their wives will attend the ceremony...