I believe that is certainly part of the issue, though the huge amount of porn-stuffs here is, in my opinion, because it is restricted elsewhere. Because there is no socially acceptable place to indulge in such behaviour (and in my opinion, there shouldn't be... sexual matters are private for medical and societal reasons, but that's another debate), when left to a 'private' place where people are allowed to express themselves, they do so to an extreme that wouldn't be there if it weren't taboo. Kinda the difference of leaving a bottle of soda a little bit open and letting it hiss out the excess pressure as you shake it, or if you leave it closed and you shake it only to open it at the end.

Though again, I reiterate, I do not advocate excessive public displays of affection. Children and the world in general doesn't need to see people with hands in each other's pants while making out voraciously in the park next to the slide. :|

THIS.

I agree with you, and as you said at the bottom its good for it to be private for that matter. But maybe it would be good if if it was more free to be more open about sexualitie but with some tact so that people aren't perverse. But yeah, its here because its acceptable