It was a little work to catch up to the speed of the piston arm. Especially so when his focus was so divided by how it felt, how hard he was, how good it was to be watched... he didn't usually have this much trouble multi-tasking, but this wasn't a usual situation either.

"Yes... better..." Dean had an idea of how it would go, but the reality was even more exciting. He liked being out of control, and there wasn't much more out of control than being tied to a machine that would fuck him for hours whether he was participating or not.