Have you ever gotten so drunk you forgot you offered the princesses' hoof in marriage to whoever brought your sister back? And how many 'es' there are in 'Princess'?
Celestia and Luna married the mane six, now they have a harem and a honeymoon to deal with. In all honesty, happily ever after isn't all it's cracked up to be. At least there'll be room for orgies.
Pinkie and Rarity throw a party to announce their relationship. Pinkie asks Rarity on a date, getting the rest of their friends to help plan it, all while Rarity and Pinkie try to help Fluttershy and Rainbow deal with their feelings for each other.
When she was in middle school, Sunset Shimmer suffered from what is called 'Middle-second syndrome'. Finding her past embarrassing, Sunset will try everything to start her high school journey quietly after moving out from her city.