Turns out Rainbow Dash and Rarity are a married couple, and have been since before Twilight moved to Ponyville. Twilight never knew this. Hilarity ensues, as well as a few feels.
Twilight Sparkle is sure that Rarity and Rainbow Dash are having relationship issues, primarily because they keep inviting her to join them on all their romantic dates.
As the summer of her teenage years turns to autumn, Rarity reflects on her last summer of freedom before college... and whom she was able to spend it with.
After accidentally injuring Elusive's dancing partner before a large competition, Rainbow Blitz swore that he would help him find a new partner and win. Unfortunately, Elusive seems to want Blitz to be his replacement.
There are times in life when one has to stop and reflect on how they came to the place they are now. For Rainbow Dash, that happens while barreling down the hall to Rarity's studio to ask her a very important question.
Nightmare Moon must come first in your heart. Always. To betray one's devotion to Her Majesty with love for another is an act of high treason: a Heartcrime. Night Chamberlain Rarity's sure she's not a criminal. But she's been wrong before.
Rarity needs a live model to practice her rusty drawing skills. Rainbow Dash is the perfect pony for the job. Now if only Rarity didn't find Rainbow's posing so provocative ...