Either that, it could be that time when Molly and Fausticorn spoke right after Luna had been banished.

Whats this “Molestia” I’ve been hearing about?

Naughty Tia! Newspaper to face!!

“I should send you to the sun instead daughter!”

“You almost ruined Nightmare Night for Luna. Heck, I don’t know why this was even made in the first place. Was it to treat your banished sister like some sort of Boogeypony figure? You know what else was bad? That Luna was accepted by society for THE WRONG REASONS! She wanted to make a new rep, not bring back the very past that ruined her. YOU SHOULD BE ASHAMED!”

Faust:  
“I cannot believe you young lady! Centuries upon centuries, millennia upon millennia you have never once gave in to these carnal desires, but these last thousand years I find you have become a crazed sex fiend! Mares and Stallions, even Foals!”
 
Celestia;  
“But Mother, I was all alone, without Luna by my side I had no one to turn too.”
 
Faust:  
“Even worse! Bad enough that I find for all those years she was your ‘outlet’! A thousand old gods of the other realms you could choose from…and instead you chose to partake from your own flesh and blood! And now you are partaking from your own children!”
 
Celestia;  
“Well technically none of them came from my own womb so ‘children’ is not quite a literal term…”
 
Faust:  
“Technicality! You are suppose to be their mother! Instead you use them to satisfy your perverse appetite! If you are to die now you will find yourself umong the first ones to be truly punished in Hell! The second circle will be your resting place, your neighbors will be Semiramis, Dido, Cleopatra, Helen of Troy, Achilles, Paris and Tristan! Blown to and fro by the terrible winds of a violent storm, without hope of rest. I have seen this circle with my own eyes, where ‘mid the gust, the whirlwind, and the flaw Of rain and hail-stones, lovers need not tell their sorrows. Pale were the sweet lips I saw, Pale were the lips I kiss’d, and fair the form I floated with, about that melancholy storm!”
 
Celestia:  
“Wasn’t it Dante who went to hell and back, not Faust?”
 
Faust:  
“Dammit Celestia I’m on a role here, don’t kill my thunder.”
 
Celestia:  
“Just saying your name’s not Lauren Dante.”
 
Faust:  
“Cheeky smartass….”

Daughter I am disappoint