Well, if he believes that sane sex marriage is a “sin”, it’s his prerogative not to marry someone of the same sex. But why force his religious views on other people?
>But why force his religious views on other people?
Because religion is also a theory about how society should live, what is sacred/holy/profane/immoral/etc, not just what someone believes for themselves.
Plus, in a sense, he doesn't force his religious views on other people. He asks other people not to step on his religious concept (the marriage as a specific sacred mystery / holy union with specific rules, etc).
Now his objection might be outdated, but it's not some outlandish idea the "beyond the pale" kind, like being in the KKK. Just a few decades ago (not in some ancient ages) most of the US (not to mention the global population) would have agreed with this, including many progressives otherwise. Heck, it wasn't even one of the major demands of gay activists themselves back in the day.
Not allowing same sex marriage steps on some people's religious concepts. Allowing mixed race couples or heathens to marry steps on some people's religious concepts.
Should a priest be allowed to refuse to wed gay couples? I think so. They can go find another priest, so it doesn't mean I am against gay marriage. I just don't see why we should force people to do certain things in their religious ceremonies. Other than that marriage is just a join table, it means nothing so there is no reason to forbid anyone from doing it.
Instead of arguing about whether priests are forced to marry gay couples now (they are not, and this is an easily verifiable fact), I think a more interesting question is - what principle is it that says it's ok for priests to deny marriage to same-sex couples?
In other words, can you please explain why priests should not be forced to marry gay couples? "Force" is a loaded word, of course - I'm not necessarily talking about armed agents going into a church and demanding that a priest perform a marriage ceremony, but rather referring to the full range of coercive actions available to the federal government. For example, if a church refuses to perform same-sex marriages, why should they get tax-exempt status?