Cropped In Her Cage
You might enjoy this nifty scenario I found over at Sex And Submission, featuring a riding crop, an iron cage, and the lovely Sandra Romain:
Spanking Blog: Adult Erotic Spanking At Its Best
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Reform School Collective Punishment Movie:
Detention House 3: Delinquent Girls Spanked Amazingly Hard
"...the girls are prepared in the reformatory’s punishment room, naked, lying on their backs on special benches, bound with their legs spread above their heads, shamefully showing the two holes usually hidden..."
Hmm… could be difficult to land with those bars in the way. I’d say a vertical downward stroke is the best bet!