Who on earth has mentioned being "anti anal, anti ‘kink’ (but can’t define kink of course) anti porn"?
I don't think a single person has mentioned anal or porn. You should not do anal or get off to porn in public. You shouldn't secretly be getting off to those things in public where part of you getting off to it is knowing that you are so doing in public.
I'll bite and define kink for you. From Wikipedia, no less: non-conventional sexual practices, concepts or fantasies.
Just like conventional sexual practices, they have no place involving children. This is what you just don't seem to understand (well you obviously do understand but are pretending not to): part of the kink (sorry sorry sorry part of the "non-conventional sexual practice") is that it involves bystanders. That is what makes is wrong*.
*No, it's not illegal; no it's not illegal to think it; no parliament won't take a vote on the basis of a MN thread. I mean wrong in the sense of much immoral. Much like other widespread male sexual attitudes it's selfish, entitled, non-consensual.