Many things happened when Pinkie Pie tried to convince her siblings to move to Ponyville. Rainbow Dash lost a hoof wrestle with Limestone, Twilight learned just how far one may shove a pony's head into a trombone and Marble got left behind as usual. This time, the shy earth pony didn't mind being forgotten as it meant they could spend more time with the first kindred spirit they have met in a long time.
Alone with kindest pony Marble had ever met, the earth pony found themselves drawn within those sparkling eyes and now must return to Ponyville in hopes that Fluttershy feels the same way.
(Commissioned by a patron! Head on over if you want a story as well.)
Warning, though this story has no sexual content and is rated E, the sequel gets hot and heavy, you have been warned.