Luna sat next to Celestia, happily covered by the latter's wing. However, one thing kept plaguing her mind, and she reluctantly shed the comfort to look questioningly at Celestia.
"Celestia, wherefore didst thee forswear so readily to thy faithful student, Honored Twilight?"
Celestia stopped smiling, her posture stiffening. "I can't tell her such a thing in front of them. It would be too great a burden on all of them, Twilight especially."
"We bethink that thee would knoweth better, lief sister. A harsh truth is preferable to a comfortable forswear, especially since that forswear wilt eventually beest hath found out." Luna frowned in disapproval. "Honored Twilight wilt has't a large temper once the lady findeth out what thou has't done."
Celestia sighed, and rubbed a hoof down her face. "I know, I know. But I don't wish to see her suffer with the knowledge for the rest of her life." She grimaced, and then added in a whisper, "Part of me almost wishes that she dies before them, so she does not have to outlive them."
"Sister, such things should nev'r beest spoken!" Luna replied in a harsh whisper.
"Luna, I don't want to talk about this right now." Celestia once more put a wing around Luna, who looked slightly uncomfortable. However, she leaned back into her elder sister. "I promise that I'll tell the truth to Twilight in the future.
"For now, let's just go home."
Hmmm...
Hey, Celestia, can you guess what you're doing wrong? Not much, just everything. Seriously, Luna, who's been away for over 1000 years has a better understanding of your student and her feelings. You've been practically raising Twilight and you can't see that you're mucking up to a disgusting degree? By the unholy Hells, you're a dumb-ass. You'd best come clean with Twilight soon (by that I mean "tomorrow") and explain why you lied, otherwise you're going to have one angry(er) ex-student on your hooves.
And I think at this point, you deserve all the anger and hate she has for you.
6607781 I think that Celestia might be in some denial over any of Twilight's (or anypony's, really) mistrust or general dislike for her, probably claiming "it's for the greater good," or that time will heal all wounds.
As she will find out eventually, time does not, in fact, magically heal wounds! Who would have guessed?
6609248 Anybody with a working brain and the superpower of common sense?
6609474 I'm not really sure how to explain it. In this story, I feel Celestia can tell when people are upset with her if she does the cryptic stuff she does, and is pained by it, but comforts herself by saying, "It's for the greater good." She has genuinely good intentions at heart, but her methods are lacking (it doesn't help that up until now, there was nobody to really tell her to stop. Most ponies see her as their infallible goddess, and trust her word).