Well how can sex be shameful? Even in the Bible it says populate the earth. You need to have sex in order to do that. However some religions are disapprove of masturabastion.
Mastur-debation of masturbation anybody?
Look, masturbation is real it happens. It is what it is. But its not real sex.
Real sex with the purpose of bonding and/or creating the next generation is obviously a beautiful thing.
I'm not here to say masturbation is wrong or right. What I am saying is that generally even a depraved person will gawk at a racoon masturbating because there is something depraved/ awkward/ lonely/ pathetic about it. Again, nearly all humans likely do it routinely and probably 99.9999% have done it at least once.
My point is that self-sex =/= sex and furthermore, if you want to do your porn fine go sneek off somewheres private and don't bother everyone else about your interest in lonely, self indulgent yet perpetually awkward escapism.
If not, you are behaving something akin to the racoon masturbating behind one way glass making a fool of yourself. And the more such a person doesn't understand how awkward they are would be like all of a sudden the one way glass becoming two way and such a person just continuing to self pleasure themselves publicly.
Non zombie humanoids wear clothes because non zombies are more than barnyard animals (zombies less than). Women and men alike generally support laws against pedos, flashers etc because public displays of gratuitous nudity and/or self-sex are just plain awkward/ pathetic/ disgusting.
The racoon doesn't make the rules. I don't either. Nobody in fact makes the rules about such things as they are like gravity. It is what it is.