No. Masturbation is a private matter, and stories about it are not suitable for public discussion as they involve private and often sexual content that violates public propriety and privacy norms.
No, it is completely unacceptable. Public places are meant for general public activities and should adhere to moral and social norms. Such behavior violates public decency and can make others around very uncomfortable.
It depends. You have the option to control who can see your Facebook Stories. You can set it to be public, visible to friends only, or specific groups of people you select when posting.
Stories of scientific discoveries are also wonderful public stories. They show the progress of human knowledge and the power of human intelligence. For instance, the story of how Newton discovered the law of gravity through observing an apple falling is both interesting and educational.
There was this time in a small town during a local fair. A man who had drunk a bit too much lemonade found himself in a long line for the porta - potties. Unable to hold it any longer, he darted behind a large carnival game booth. However, he didn't notice that the booth was on a bit of a slope. As he started urinating, he lost his balance and ended up tumbling down the slope still mid - stream. His friends couldn't stop laughing when they saw him all wet and disheveled at the bottom.