Plastic Ono Bag
Roll a plastic freezer bag (ziploc, etc) inside a towel, making sure to leave the bag opening in plain view and for easy access. Adjust tightness of your roll by inserting penis, use like fleshlight. When the tightness is ok, put the bag underneath your mattress. Squirt in a generous amount of baby oil. Your weight on the top gives extra pleasure. Put your dick in the hole and hump away. The handsfree orgasm is best.