Have your ship go through something amazingly fluffy and it turns out that it's just another character's fanfic of the two

Or

If you want your readers to chase you with pitchforks you can make it where it's one of the characters in the ship is writing it: and they're not together, the other is dead, or it's a suicide note with the last bit saying "it's such a shame that we couldn't live this life"

Peace
  ~GayWeabooTrash