This is just mesmerising. Your amazing, smooth shaft, totally rigid and straining to contain your cum, and those slow strokes coaxing you to the point of no return, and then the throbbing urethra and hands-free spurting... Magical. I want to cum NOWWW!
It is amazing how powerfully the shaft contracts. My much smaller dick does not visibly contract, and if I take my hand off, the cumming stops... but there isn't much cum to begin with. He is very powerful sexually.