Using an enema bag, I filled my bladder with as much saline as I could take, then held it while I masturbated to orgasm. After I inevitably spilled, spurts escaping with each orgasmic spasm, I slid the tube back into my stretched urethra and topped my bladder up, making it painfully full once again. I repeated this, sometimes losing control entirely and emptying my bladder during orgasm, sometimes just letting a trickle escape. In the end, a full gallon went into my bladder, stretching it, then came helplessly out again!