I'm realizing most of the posts in this thread about parents catching us masturbating, and my earlier post was about them finding out I was masturbating (since I was a very late bloomer, my pediatrician got me to admit in front of my mom at my sixteenth birthday exam that I had started masturbating to ejaculation a few months earlier). So here's the one time I was caught:
After the family practitioner surprised us all by not examining my brother and me in front of my mom about a year after that last pediatrician exam at 16 (they put me in my own room and my mom with my brother in a separate room), my mom was still trying to figure out whether what the pediatrician said was true -- that I'd not finish puberty until I was in college.
So since the doctor no longer was letting her see my development each year, she started finding excuses to come into the bathroom while I was showering -- aways supposedly looking for something.
But one of the first times she did this -- probably less than a month after that family practitioner exam where I was on my own with the doctor for the hernia check -- I had been masturbating in the shower when she came in. I had been in there longer than usual, so she probably knew what was going on. This time, instead of coming in to look for something, the excuse was that we were running late to be somewhere (again, I'm pretty sure it was a fake emergency we had to leave for, because I'd not have masturbated if I knew I needed to be somewhere on time). So she came in and said we were late, and to get out of the shower. I said I'd be out in a couple minutes, but she insisted right then. so I quickly rinsed off and turned off the water. I said I'd be ready to leave in 2 minutes, and she insisted I get out of the shower. As I stepped out, my little five-and-a-half-incher still pointing straight up at the ceiling, she was standing there holding my towel in one hand and my clean undies in the other. I reached for my towel, but she stepped back and said to hold on a second. She said the last time she saw my "peepee" pointing up like that was at the pediatrician on my 16th birthday. She said she thought it may have grown a little since then, and asked if I thought so. I said I guess so (she was right -- it was half an inch longer than a year earlier, but as long as it ever was going to get). Only then did she give me my towel.
I learned my lesson and stopped masturbating in the shower. I quickly realized that when she'd come in to the bathroom while I was showering, if I kept my back toward her, she'd keep "looking" for the thing until I finally faced her. From then on, when she would come in when I was showering, I would fairly quickly turn toward her until she saw my penis, at which point she'd usually "find" whatever thing she was fake-looking for, and leave. This indeed continued into college and even grad school when I'd come home for a break, so she finally got to see me at Tanner stage 5. She never saw my erection after 17, but if she had, she'd have seen it never got any longer, though it did get thicker until I was in college. I have no idea if she noticed the extra girth all those times she saw me flaccid in the shower into my early 20s.