That's interesting you should bring that up. People often forget that in the sacrament of marriage the church teaches that the sacramental action happens between the hearts of the two individuals who are betrothing their love to each other, the priest being merely an incidental witness to publicly confer the church's blessing. The priest is therefore not "confecting" a sacrament that magically renders the couple married in the eyes of the church. 

This is one of those instances where the church actually gets it right and has the wisdom and humility to accept that the real nitty-gritty is happening within people's hearts, not on account of anything the priests does. Now if only the church could accept the fact that that's just as true for gay people as it is for straight people. Acknowledgment of that would go a long way to begin the enormous task of healing the deep wounds the church has inflicted on a countless throng of gay people who remain part of the Communion of Saints.