That river in Egypt

His penis was already fighting to get hard, holding all the remaining blood in his body down there in the process. But the instant those words left her mouth, his dick went into overdrive. It didn't matter that she was lying, his cave-man brain heard it. With Herculean strength, it strained so hard against the cage trying to get hard that the blood on the floor got sucked through the straws, through the forkholes in his eyes, and all the way down his body to his dick as it tried to grow. His brain didn't know that he was being held against his will or that she was forcing him into submission, it just knew a pretty girl was saying those words and ran with it. She smiled, maybe it wouldn't be so difficult to make him fall for her after-all
"Hehe that's right dear. How would you like it if I licked tiny circles over the tip of your cock until you blew your load? Would that feel good?"
All the blood across the walls, floor and ceiling retracted towards his body, getting drawn back in and sent to supply his caged little cock with an erection. The straining was like an unstoppable force meeting an immoveable object. While his dick fought to get hard, the cage stayed strong and never buckled.

Before long, the entire room was clean, not a single drop of blood in sight. She knew that his penis could only hold all that blood in for so long before it started leaking out his eyes again so she had to move fast.

True story btw :P