As a first story- excellent! The start is a bit slow, but once it gets going, it builds well, and is way sexy. I will score it 5, but there is room to improve.
You tend to tell, not show. Especially at the beginning of the story, this tends to drag. One of the many ways to draw a reader in is early dialogue. To do that, you would have to start your story in the middle- at the line where the man says:
“Little girls should be careful in what they wear.” His voice an insidious whisper in my ear, “They may attract dangerous men.”
that would be a very bold opening. You could then jump back to the backstory of her shyness and arrival, compressing and editing, and interspircing it with the dance and dialogue.
Specific notes:
I moved carefully through the bodies, clothed entirely in black
Are the bodies clothed in black, or the narrator?
Also, 'bodies' suggests corpses, at least to me.
If you don't want to start in the middle, you could have used dialogue with her friends " Here's a drink" " How Nice, thanks!"
The throbbing drum beat instantly made me feel sexy.
nice, but in passive voice. "I felt sexy " is stronger, so use " I felt sexy as the throbbing drum beat invaded my belly."
The need to dance overwhelmed me
same point. " I was overcome by the urge to dance."
There was just no other way to describe him
this sentence struck me as surplus, and broke my focus.
I felt small next to him
" Small " is a very overused, therefore unemotive, word. If you need the point of her being intimidated by his size, use stronger words. even say so: " He was so much larger than me, I felt like a little doll held by a giant."
I’ll just give him this one dance and be done with him
present tense- looks like a shift. For internal dialogue, use single quotes, so the reader recognizes the context.
At this point, the dialogue really picks the story up. But, do you intend the dialogue to seem stiff, or do you just need to practice?
There’s no way something like this would happen in a room full of people.
Looks like a tense shift here. Also, the unreality breaks the spell of the story. Try " This couldn't be happening. But it was."
My corset was pulled away
Another case of passive voice, In this spot, it really breaks up the fast pace. " He ripped my corset free."
His indifference to his own pleasure and his feeling of conquering me made my body insane with pleasure and also fear and anger.
Big 'no no' here- shift of POV. She can't know how he feels, just what he expresses. " His seeming indifference..." " his conquest of me...".
A friend of his
How does she know they are friends? Isn't he really just another guy?
That's it. Actually a short list for the length of the story.
Non-consent isn't usually my thing, but I liked this story. I look forward to more.