You're against gay marriage, so you don't want to consider that as an option when talking to people about your marriage or other marriages. If that's correct, ok.
I'm against calling unions between homosexuals marriage.
I'm fairly neutral on whether the government should sanction those unions at all. I think the law already treats everyone equally, and personally I would rather the government not sanction anyone's relationships at all, but those are only loosely-related issues that really don't reflect on the debate we've had here.
To the point where if someone thought you were a different sexuality than you actually were, it would be like "No, I wouldn't like that steakhouse, I'm a vegetarian" and everyone moves on.
That's all well and good so long as the vegetarian doesn't demand that the entire group must only go to vegetarian restaurants because they are vegetarian. Or that all restaurants should be forced to serve vegetarian food.
Similarly, homosexuals shouldn't demand that everyone cater to their needs or be accepting or tolerant of their choices.
There's no judgements, no being upset about being confused for something you're not.
I don't want to be confused for anything I'm not. That's true whether someone thinks I'm a flower, an astronaut, or a homosexual. Generally speaking, I'm in favor of things that help prevent any confusion surrounding what I am or am not, so that people do not think I am something I am not.
FWIW - My opinion is I'd be ok with NBC showing porn as long as it was easily "blocked." As in, it's not Channel 4 (where I live), it's on a channel that's harder to stumble upon on accident. Or, have each cablebox have an easy, well-understood option to block the channel once porn is being shown. Otherwise, there isn't anything too bad with that.
I'll use your reasoning here:
I'm in favor of homosexual relationships as long as they can be easily "blocked" - or rather, they aren't public. I don't want to stumble on a homosexual public display of affection by accident. Otherwise, there isn't anything too bad with that.