Luna: Ah, yes, the All the paperwork is done! private little celebration we have sometimes. When in private, she likes her fire water liquors and I like a good stout ale. Public appearances require much more dignified drinks. I often get asked if I like moonshine or not and its okay, but making it my drink of choice just seem vain.
Celestia: Im just glad there were no ponies there to witness both our severe drunken mood swings or my rather unorthodox sun raising.
I’ll gladly headcanon this. After all, heavily drunk people have trouble walking or gesturing.
The guards know. So does the servants. They just don’t talk about it.