Fifty Shades of Grey has likely influenced Twilight fanfiction in terms of the exploration of more adult themes in a more explicit way. It may have given some Twilight fanfiction writers the courage to delve deeper into the physical aspects of relationships, though still within the boundaries of what's acceptable in fanfiction. However, it should be noted that not all Twilight fanfiction has been influenced in this way.
Fifty Shades of Grey could have influenced Twilight fanfiction in terms of the marketing and the popularity of a certain type of romantic - yet edgy - story. After Fifty Shades became so well - known, some Twilight fanfiction writers may have tried to attract more readers by adding elements that were similar to Fifty Shades, like a more intense focus on the main characters' sexual tension or a more in - depth exploration of the male character's darker side. But of course, there are also many Twilight fanfiction works that remain true to the original Twilight themes and stay away from such influences.