I have got two nice nipple suction devices that I use to keep slave 0 nipples tender all the time. Out of curiosity I used one on his glans. First I wrapped his dick with a black rubber strap, then I put the cup on the head of his dick twisting mechanism to suck his swollen male meat into the tube. How wonderful. I can pull and twist his dick around by the firm grip of the tube. My creativity delights over an over again.