Well, '50 shades of grey twilight fanfic' is basically a type of fan - made story. Since '50 Shades of Grey' has some themes of a rather adult nature and 'Twilight' has its own set of characters and a world, when combined in a fanfic, it could be about reimagining the Twilight characters in a more sensual or intense relationship - like scenario, similar to what was in '50 Shades of Grey'. But this is all in the realm of fan - created content.
A '50 Shades of Grey' Twilight fanfic is a work of fan - created fiction that combines elements from the 'Twilight' series and the '50 Shades of Grey' story. It might take characters from 'Twilight' like Bella and Edward and put them in situations inspired by the rather racy and complex relationships in '50 Shades of Grey'. However, it's important to note that such fanfics are often not officially endorsed and can vary greatly in quality and content.