This is a rather short story about Dash taking time to "practice" the art of lovemaking with an unknowing Fluttershy as the test subject. Not much else can be said, apart from this was the fic that invented the term "gentle rape". And I am really not sure what to rate this accurately as. Since while it technically is rape, it is also kind of sensual...

Ugh, basically, if you want to read about Dash taking her time with a unsuspecting Fluttershy, then have fun, this story might fit you.