The phrase 'gay master shit story' is very unclear. 'Gay' refers to sexual orientation. 'Master' could imply someone in a position of authority or control in a relationship perhaps, but'shit story' is a very strange and unappealing combination. It might be some kind of inside joke or a very poorly named piece of creative writing in the gay community, but again, this is just speculation without further context.
I'm not entirely sure what a specific 'gay master shit story' would be as it's not a common, well - defined phrase. It could potentially be some sort of fictional or anecdotal story within a particular gay subculture, but without more context it's hard to say.
Well, 'gay' relates to homosexuality. 'Master' can have multiple meanings like a dominant figure or an expert. However, 'shit story' is quite vulgar and not a typical term. It could be that someone is trying to describe a rather strange or bad experience within a gay - related context that involves a person in a master - like role, but really, this is all just guesswork given the odd nature of the phrase.