I'm not sure specifically which 'Zac Brettler story' you are referring to. There could be many people named Zac Brettler. Can you give more context like is he an artist, an athlete, or something else related to him?
There is no evidence to suggest that Zac Efron is gay. Zac Efron has been linked with female co - stars in the past, which indicates his heterosexual orientation.
Definitely not. Luther is a work of fiction. The creators crafted the story and its elements to provide viewers with an exciting and thrilling viewing experience that doesn't have a basis in reality.
There could be. Fanfic writers come up with all kinds of creative and diverse stories. However, it's not something that is mainstream or widely known in general. Zac Efron is a popular actor, but the idea of a 'gay lemon fanfic' is a very niche concept. You may have to dig deep into fanfic communities to find out if such a thing exists.
Most likely, these stories originate from baseless speculation. Maybe some people just like to spread unfounded rumors in the entertainment industry. There's no real substance to them.
Yes, Zac Efron is a popular actor and fanfiction involving him, especially those with romantic elements like kisses, can be quite popular among his fans. They enjoy imagining different scenarios with their favorite star.