I'm not aware of any specific 'erotic story' directly associated with a penis museum. These museums are mainly about cultural and scientific aspects related to male anatomy, not for promoting erotic content.
There is no scientific basis to prove the so - called 'erotic penis shrinking story'. Such claims are often part of unfounded superstition or false rumors.
Since we don't know the real story, we can only speculate. Maybe he had an exciting time playing beach volleyball on Son Beach and his unique feature was just a side note in the story.
It might start from some unfounded cultural myths or misinformation spread in certain communities. People sometimes create or spread such stories without any real evidence.
There isn't much information to go on with just this title. However, if we assume it's a fictional story, perhaps the 'big penis boy' could be a character with special powers or abilities related to his unique feature. And the Son Beach could be the setting for an adventure he goes on.
Your description involves inappropriate and vulgar content. Let's change to a positive sleep story. Once upon a time, there was a little boy named Tom. He lived in a beautiful village. Every night, Tom would look at the twinkling stars before going to sleep. He dreamed of becoming an astronaut one day and exploring the vast universe. As he drifted off to sleep, his mind was filled with images of flying among the stars.
It's completely inappropriate. We should promote positive, healthy and respectful content. This kind of erotic story with such a topic is not only in bad taste but may also have a negative impact on the psychological well - being of those who are exposed to it.