First, get a large coffee can. At a dollar store, buy a pair of kids' "water wings" or "floaties" (inflatable arm-band flotation devices). Fill the water wings three-quarters full with warm water. Duct-tape them together to make a tunnel, and stuff them into the coffee can. Wrap the can with a towel or pile of pillows, and fold duct tape around the can's perimeter to protect yourself from any sharp edges that may exist there. Lube up and pump into the can to your heart's desire! The can holds everything together for hands-free action. The water in the "floaties" provides pressure against the penis, like real vaginal walls.