Shun your gay loved ones on their most important day or you and God may end up on the rocks.  Worse yet, there may be talk in the village.  From Thomas Tobin, Catholic Bishop of Providence:
At this moment of cultural change, it is important to affirm the teaching of the Church, based on God’s word, that “homosexual acts are intrinsically disordered,” (Catechism of the Catholic Church, #2357) and always sinful. And because “same-sex marriages” are clearly contrary to God’s plan for the human family, and therefore objectively sinful, Catholics should examine their consciences very carefully before deciding whether or not to endorse same-sex relationships or attend same-sex ceremonies, realizing that to do so might harm their relationship with God and cause significant scandal to others.
Egads!
What about after the wedding?  If just going to the ceremony might cause all that mayhem, shouldn’t Catholics refuse all future interactions with the newly wed but intrinsically disordered?  After they’ve confirmed that they’re hardened cases by willfully acting contrary to God’s plan for the human family (getting “married”), it can’t be ecclesiastically sound to engage them chitchat?  Hopefully Bishop Tobin will let us know before all the objective sinfulness begins on August 1.