Y'allin'

At a royal invitation, Applejack refers to a single foreign dignitary as "Y'all," and it blows up all of Equestria. Well, maybe not, but Twilight Sparkle is no less frazzled about it.

While welcoming a foreign dignitary to Princess Twilight's Palace, Applejack refers to the single monarch as "Y'all." This, of course, causes the entire Kingdom of Equestria to explode into flames.

Okay, maybe not explode into flames, but it could happen... right? Just ask Twilight...