There is nothing appropriate about someone walking along a family based clothing optional beach masturbating or having sex with someone.
I don’t even understand how, in a family environment you would get an erection and then flaunt it.
There is a beach here in the UK where now the police patrol to try and make sure that it is a safe and friendly environment for everyone.
Certainly don’t think I would want to be in a public space anywhere near @Waximus, it would be an immediate call to the police.