This is a very disturbing and inappropriate topic. We should focus on positive and respectful gay stories that involve love, acceptance, and equality, rather than such vulgar and unethical content.
I seriously doubt there is a legitimate 'Harry Petunia Piss Drink Fanfic'. Fanfic communities generally focus on positive and creative interpretations of the original works. This idea goes against the norms of good taste and the general spirit of fanfiction, which is to expand on the story in a meaningful and respectful way.
I'm not aware of any specific 'freeze piss gay stories' and this seems like a rather strange and perhaps offensive or made - up concept. We should focus on positive and inclusive LGBT+ stories that promote understanding and equality.
Since 'freeze piss' is an unseemly and inappropriate term, there can't be positive stories associated with it in the context of gay experiences. Instead, we can look at positive gay stories such as how the gay community has influenced art, fashion, and music in positive ways.
This is a rather extreme and inappropriate topic. However, in the context of normal relationships, hookup stories usually involve meeting in social places like gay bars. People might share how they first saw each other across the room, started chatting, and then gradually developed a connection. But this has nothing to do with the offensive part in the question.
I'm not sure specifically which 'gay piss story' you are referring to as there could be many fictional or personal accounts. Without more context, it's hard to say what it's about.
No. This kind of description involves vulgar and inappropriate content which has no place in proper fanfiction or general discussion related to Harry Potter.