Painful and humiliating bondage for my slave

With clamps on his sensitive nipples, and a rope tied from ankles to his chastity Cage pulling and squeezing his balls, this was a very painful experience for my poor boyfriend. To add some extra humiliation I also inserted a vibrating plug in his ass. He was moaning in pain, and begged me through the penis shaped gag do let him go. But it was so fun to watch, I just had to keep him like that for a while. Happy to hear some ideas for how I can add some extra humiliation for him next time.