Holy fuck. I just did this and it was awesome I only used 4 pins around at the bottom, put my cock in, hurt a little, then, the harder I got the more it hurt, the more it hurt, the harder I got. Going to put more pins in and try again. Best part was as I got harder, the pins pushed into my coxk so the tube pushed our along as my hard on grew. I think I need to "secure" to be against my body then intensifty will be greater.