You can't always lie comfortably on your back and wait for an orgasm. I've now thought of something mean where the slave is challenged a little. He had his neck cuff put on. The shackles for his hands and feet were attached to the bar behind his back. But today there was no jerking off. Today I drained his cock with electricity. To do this I put the electrodes on his cock and pulled a condom over it. I milked his cock in this uncomfortable position. It was fun.