Sure has put the Southern Baptists at odds with many of the
“mainstream” Protestant churches. Pretty effective recruiting strategy, as well as being on the right side of the theological question regarding marriage.
Whatever “gay marriage” may be, it is not a Christian sacrament. If you have even the least acquaintance with the various works of the Marquis de Sade, one of the themes was the desecration of all things religious, and a celebration of unnatural unions.
The two largest conservative Lutheran churches - WELS and LCMS are true to the biblical teachings on homoseuality and marriage. There are other smaller ones that are too.