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Original Description:

“Darling. Do you need somepony?” The young stallion spun around and looked back at the balcony door he’d stepped through. Standing in the doorway, backlit by the light coming ballroom was a stunning leather clad valkyrie. She stepped out onto the balcony and came to a stop about 6ft in front of the stallion. By the leather jacket she casually draping over her right shoulder he assumed she’d just arrived at the event.
Giving the stallion a quick looking over she addressed him. “First time to one of Luna’s Lunar Midnight Balls?” The stallion swallowed and nodded his head. The mare smiled sweetly. “Don’t worry darling. There’s a first time for everypony, and there’s no shame in asking questions. That’s how we learn dear. Just be tactful about them when you ask.”
The stallion seemed to have finally realized who they were speaking. “Um, aren’t you Rari–”
The mare gently tapped the end of her crop on the stallion’s lip. “Ah! Okay darling first lesson! At the Lunar Midnight Ball one is suppose to come as a character of their own creation. A persona. Tonight you should, and will, address me as Lady Diamond. Do you understand darling?”
“Um yes, Lady Diamond.” The stallion said.
The white grinned at him. “So. Darling. Do you have a partner for tonight? Another guest you’re with?”
The stallion shook his head. “Um, no ma’am. Uh can I still call you ma’am?”
Lady Diamond laughed softly for a moment. “Yes Darling that is an appropriate way to address me. Although depending on how things go tonight I may insist you refer to me differently.”
She stepped even closer and smiled impishly. “But you didn’t answer my question darling. Do you need somepony?”
A Patreon reward for Caraig. He wanted me to draw Rarity as if she was to attend an anthro version of Luna’s Midnight Ball that I referred to awhile back.

>>3343882p
And of course Lady Diamond is the name that Rarity has adopted for her new line of more adventurous fashion items.