When you get an erection in the shower, probably because you constantly masturbate whilst in their or because you just soaped up ur penis and balls and the massaging made it harden.
While I was having a shower, I took a handful of liquid soap and rubbed it all over my penis. The sensation was awsome and I got a Shower Tower in seconds. I was like hey why not. I wanked off nice and fast with my lubricated dick and the orgasm was great as I didnt have to worry about where the jizz flew.