I'm not sure specifically as it could vary greatly. It might be a fan - created story related to the 'Twilight' series that focuses on the concept of 'innocent sins'. Maybe it delves into the characters' moral or ethical struggles within the Twilight universe in a new and creative way.
You can start by looking on popular fanfic websites such as Archive of Our Own (AO3). It has a large collection of Twilight - related fanfics, and there's a good chance you'll find 'innocent sins twilight fanfic' there if it exists.
Twilight is not a fanfic. It was developed independently by Meyer and became a highly popular series. The story, characters, and plot are all original creations of the author.
Twilight was not derived from a fanfic. The story was created independently by Stephenie Meyer, and it gained popularity on its own merit. There's no connection to any pre-existing fan-written works.
Definitely not. Twilight has nothing to do with MCR. It emerged as a separate fictional creation that gained popularity on its own merits rather than being related to MCR in any way.
Twilight and 50 Shades have no direct connection. Twilight is a popular vampire-themed series, while 50 Shades is a romance with a different focus. So, Twilight is not a fanfic of 50 Shades.