I did not hear the show and so cannot comment on what the priest said. Perhaps he misunderstood the question asked or perhaps you misunderstood the answer given.
To the general question of attending same-sex "wedding" ceremonies, I can say that the Church has forcefully condemned the idea that there can be any true marriage between anyone or anything other than one man or one woman (example
). Given that position of the Church on the issue, I cannot recommend that Catholics attend these kind of ceremonies for any reason whatsoever. Rather than merely a travesty, I believe such ceremonies fit the exact definition of sacrilege
- Marriage is one of the seven sacraments of the Church (CCC 1660).
- The abuse of a sacrament is a sacrilege (CCC 2120).
- The deliberate action of aping a sacrament is an abuse of a sacrament because to do so treats that sacrament "unworthily" (again, see CCC 2120).
- If no true marriage is possible between two persons of the same sex (as the Church affirms), then to attempt marriage under such circumstances treats the sacrament in an unworthy fashion and is therefore sacrilege.
- Such abuse of the sacrament of marriage is especially serious when one or both parties involved is Catholic and therefore should know that marriage is a sacrament and should know that it is a serious offense to abuse sacraments.
Under such conditions, how is it in any way "charitable" to support a relative in committing sacrilege? Charity is not the same thing as affection, sentiment, or good feelings. Rather, charity is "the theological virtue by which we love God above all things for his own sake, and our neighbor as ourselves for the love of God" (CCC 1822
What are the rules for attending weddings?