Yeah, I think this is a key part, if not the entire source, of discrimination against gay people.

It should go without saying that homosexuality is no more a state of action than heterosexuality is. Gay people aren't doing anything to be gay, they just ARE gay. They fall in love the same way as straight people, they pay their taxes the same way, they serve in the army the same way, they go to church the same way. There's no part of being gay that requires anything extra.

But some straight people think of homosexuality as something extra, because when they think about homosexuality, they just can't stop thinking of two men doing each other up the bum. And it squicks them out. And because of this extra layer they're adding, they think that homosexuality is different in some meaningful way to heterosexuality. They then try to use the law as a shield against their own intrusive thoughts.

Recognising the objective fact that two men or women are married is not condoning their marriage (whatever that even means, there are lots of reasons not to condone some straight marriages). It doesn't require tolerance towards actions, unless the person in question is imagining a very specific set of actions. Again, business owners don't have to like it. They just have to stop letting their imagination run away with them for long enough to do their jobs.

I find the solution to this is simply to avoid imagining strangers having sex. There are a lot of straight people who, if I imagined them having sex, would cause me irreparable psychological damage. The vast majority, in fact. And that's before we even talked about the specific activities they might get up to (anal sex being extremely low on the list of potential horrors).