When I was much younger, my family and I were at my grandparents' house and since they were just inside talking, I was out playing with the trucks I brought. I was probably out there for at least an hour, and I guess from making roads and crawling around in the dirt, my clothes were covered in it. When I went back inside, I remember my mom getting really angry about it and that she said all of my clothes were going to have to be washed. While I was stripping off, I started complaining about having to take my clothes off, but when I got to my underwear, she said they would have to come off too. No matter how much I cried about it, she said it was my own fault and I shouldn't have been playing in the mud. Still crying, I slowly pulled off my underwear and handed them to her.
She started the washer and I followed her back upstairs. When we got to where the everyone else was, my grandma made a joke about how cute it was, but I was really embarrassed and tried to cover myself as much as I could. I probably stood there for about 10 minutes with my tiny, now hard penis covered with my hands. My mother then said that I could go to the back room to watch TV, so I ran off as fast as my feet could take me. As soon as I got to the room, I closed the door so I wouldn't be seen anymore. Feeling a little more comfortable about it now, I turned on the TV and laid on the floor on my belly. I stayed there for a while watching cartoons, but every time I moved around a little, I noticed how nice it felt with my still hard penis wedged between the carpet and my belly. I then started moving around on purpose, loving the feelings I was getting. After a couple minutes, I dug my toes into the carpet and started grinding against the floor. It only took about a minute, but I then lost my breath, and my penis felt so, so good. I had no clue what happened, but about the next hour or so I kept rubbing against the carpet, feeling that tickling a couple more times before my mother came in and tossed my my clean, hot clothes. At that point, I didn't want to get dressed, but did and went back down with the rest of the family. I didn't know it at the time, but doing that gave me my first orgasm. It also wasn't until much later that I realized my mother had caught me masturbating.
After that day, every chance I got, I would go to my room, close the door, get naked and rub against the carpet or on my bed until I got that tickle. Soon after, I started producing cum and I learned the right way to masturbate. About 10 years later, I still masturbate all the time, and it still gets me horny thinking about if she told everyone what I was doing that day.
I'm actually glad she made me go naked, because if she didn't, who knows how long it would have taken me to start masturbating, and then I would have been missing out.