I found this interesting documentary about masturbation on Amazon Prime. Sticky: A (Self) Love Story (2016) ⭐ 6.4 | Documentary, Comedy It's called, "Sticky: A (Self) Love Story" The documentarian is a guy that went to Catholic schools growing up and he endured the shame and guilt of masturbation. It covers a variety of topics, including the "morality" of masturbation, the history of masturbation as well as masturbation compulsion. It's a little over and hour, but it's worth a watch if you were raised to think that masturbation was bad and unhealthy.
There was never any mention of masturbation in my childhood. When I started masturbating at about 12, I think, I knew to do it privately. Well, I stood on the landing outside my bedroom because I would here sooner, if anyone were coming upstairs. I would have more time to react/run back to bed. I don't know where that "etiquette" came from. As an adult, I'll get naked with female friends at the drop of a hat and I've openly masturbated when I've been asked. So, back on topic, I'm sure that documentary would be interesting to those who were suppressed but I suggest it may help others understand more about others.