In response to a prompt by Admiral Biscuit on the Prompt-a-Day group thread.

"Princess Celestia?"
"Yes, Twilight?"
"So... I was a unicorn before my ascension, and Cadence was a pegasus... if you don't mind my asking, what species were you and Princess Luna before you became alicorns?"
"Well, Twilight..."

I do not own the cover art.