During my slave experiments I found out that the male psyche can be easily broken with symbolisms. Seeing phallic objects crushed by high heels just before their eyes has a nice intimating effect. Squashing a banana with my shiny black pvc boots has just that effect and makes the slave loose all hope while I unleash my heels on his dick and balls for real making him cringe in pain. His soft flesh offers a nice resistance that I can feel at my delicate feet inside the boots.