Celestia and Luna are alicorns that live for thousands of years. Twilight is forced to watch her friends become old folk, because of Celestia. I think that's kinda harsh for Twilight even though she'd never asked to be a princess, only a student.
Relaxsssssssss....it was just a joke..thats why I was using derpy as the voice of my comment.. (cause all moms in the world and hasbro agrees derpy is the offensive pony lol )... a joke i made in march by the way... a little late to reply to it..
also I sure you Twilicorn has nothing to do with the existence of a season 4 ... that would be thanks to a little thing call the magic of "demand and supply "