Here in San Francisco there are various wrinkly old dudes who walk around town naked. Not something I would do myself, but it doesn't seem to hurt anybody.

There's a big difference between just being nude vs., say, performing a striptease which is explicitly sexualized or flashing a particular person which is a kind of personal attack.

What crimes are you referring to, and are you saying they should continue to be crimes?

“Aroused” states, touching, exposing to specific individuals, etc seem like pretty obvious lines.

I think most people can tell the difference between “being nude” and “being sexual”.

Well for starters. Public urinating shouldn’t be a “sex crime” like some jurisdictions have made it. And of course this is assuming the perpetrator isn’t doing it as some kind of personal fetish obviously.

Why doing something is ok until you dont get pleasure from it. Whats wrong with experiencing pleasure. Are we so envious of that but on same time ashamed to admit that?

It is not okay to include others in your sexual activities without consent. That's the line. Getting aroused by doing something in the public / been seen doing something means involuntary participation of others, which is not okay.

Yes so thats the question, why do you not concent to someone enjoying without harming anyone. Lets say i ecstatically enjoy sunsets by the see. Should i be forbiden to enjoy them because i enjoy them a lot more than nearby standing people?

Targeted exposure and sexual aggression. There’s a difference between “hey dad why is that person naked on the train” and a person masturbating at you while you’re heading to work. Sex crimes due to nudity, or eliminating, are unjust.