My parents married very young, and I was born 11 months later. After their divorce, I was raised by a single dad who is only 20 years older than me. Long story - my dad was always very open with me like nudity, jerking off and etc. My favorite place to jetk off as a teenager was in the shower. While I wouldn't say rubbing one out in the shower was public my dad walked in a few times. He jokingly told me that I was going to " pull it off". I never shut my bedroom door when I was jerking off. Yes, Dad walked in a few times. When you are lying in bed naked, with a raging boner, it's self explanatory what you are doing. I wasn't embarrassed and neither was my dad. He would say "I'll talk with you later. Enjoy yourself".