It is indeed more closely to being one of universal relevance, that is for sure the case. However, by such I have written, I am refering more to how heavily a burden on identity sexuality is conceived as.

"But if we start imagining how society could be different, let's go with one where sex really isn't special. If someone asks you for sex, it's rude not to have sex with them, just as today it's rude not to say "hello" when someone greets you. No need for a private place, just do it wherever you are. And why not the little kids too? Somehow I don't think this is a very appealing society to girl lovers, to see your special little girlfriend giving or getting oral with anyone who asks. Maybe for some it would be appealing."

Well, it depends here, for you are asking said person for it, meaning you must respect given response emanating on behalf of the other party. Sex not being conceived negatively is not the same as equalizing all acts to be same, just as you cannot equalize two genders to be exactly the same, given their biological differences.

Anyways, if I were to follow up on your example of such society. I would agree that it would be rude to demand from other individuals and expect to receive what you always demand without considering the desires of the other party, whether such is with sex or any other act.