You are very likely female, and you very likely examine characters for their "slashability". Though you insist that your stories don't circle around love and sex between attractive characters, they do.

It is also likely familiar to you that at a certain point in your story, a character (or more) discovers that he (and rarely even she) is gay, and starts a relationship with another character.

Your fanfiction meets the taste of many, especially if your pairing happens to be between two attractive males that are straight in canon.

You probably wrote something about Harry Potter falling in love with Draco Malfoy, Legolas starting a secret romance with Aragorn or Obi Wan being a sex sklave of Han Solo. If not, you probably still consider to do it.