Ultimate shoulder rides

Telling you about my first shoulder ride experience is long overdue. At long last, here it is.
When I was young, I served for a summer as a counselor at a summer camp for little kids. After lunch, while the kids slept (or pretended to), WE played. The camp had a small swimming pool, and we played with a large beach ball: two or three WOM pairs against two or three other pairs, fighting to get the ball by whichever means. An unorthodox version of water polo.
My rider was a smallish blonde, as wiry as she was pretty. Her thighs and legs put an iron clamp on my upper body. She went at it with all her (our!) might. It was wonderful! I can't say that I was sexually aroused, but I was in heaven.
Unfortunately, this bliss did not last long. The camp was under the ultimate responsibility of some nuns, and as soon as they heard about our fun, they stopped it.