I don't think there is anyone reading that doesn't have a memory of masturbating in the tub, the shower or watching themselves in the mirror.
My first experience masturbating and having a climax was in the tub when I was 13. I had been having erections and wet dreams for some time and had heard older guys talking about beating their meat and making it cum but didn't know how to do it.
One day when I was washing I had a hardon and was soaping it and it felt so good I kept going and all of a sudden white stuff started shooting off? I did it again the next day and it became a habit. It eventually led to teaching my close friend to jerk off and learn to cum.
I was embarrassed beginning to get a hardon on in the group showers at boarding school and usually tried to hide it. The first time I caught someone jerking off in the shower I got a hardon just watching. However my roommate caught me one day and we ended up masturbating together.
The word got around and after a while it was no big deal for someone to get hard when soaping up. Seeing someone else with a hardon was catching and whoever was in the shower would get one too.
Eventually it was routine to masturbate in the shower and no one objected. In fact it was more like a daily circle jerk whenever someone in the shower was in the mood.
From the many stories I have read on Solo Touch it seems it is as prevalent with females as it is with males.
Sometimes I go to the Solo Touch archives and type in what interest me at the time. There are so many good contributions available from men and women on almost any subject. For example: type 'In the shower' in Search Solo: Google and you will find page after page of arousing MM, MF and FF stories in the shower. I've attached a few I think will turn you on to masturbate to.
I hope you enjoy your climax as I'm going to in a few minutes.